Amnesiac Dissonance

"10,000 years of unerasable acts and permanent facts The record of my unspeakable crimes In previous lives, in previous times Indelibly stains the pages of history"

- They Might Be Giants, Reprehensible

Amnesiac Dissonance occurs when a good or evil person suddenly remembers their past of the opposite alignment. This becomes the epitome of Man versus Himself (or Herself) as the values and memories of their past self collide with their current self. This can result in a complete Face Heel Turn or Heel Face Turn, or give a shade of grey to the character that they didn't possess before. Reincarnation can be substituted as a type of spiritual amnesia.

This is not possession, or merely being Brainwashed; this is the self, one's own Good and Evil, conflicting in the most direct way possible. The darkest result is the tragedy where whatever goodness might have been is erased. It requires Heroic Willpower to continue being a good guy when remembering The Dark Side and the powers it enables. Sometimes, though, Redemption Equals Death.

Note, Heel Face Brainwashing and then coming out of it may lead to this.

This tends to be more the good character remembering an evil past because Amnesiacs Are Innocent, but it's only a tendency. May overlap with The Killer in Me.

A variation may be that the person never gets their memory back directly, but does find out who they were previously and has to deal with the implications; be they crippling guilt over past evil, or longing for the simple pleasures after petting the dog.

See Identity Amnesia, Loss of Identity, and Amnesiac Liar. Compare Lost in Character.

'''This is always a huge character Spoiler. Please take care before reading these examples.'''

Anime and Manga

 * Happens several times in Angel Sanctuary, subverted with but played agonizingly straight with
 * For the first two seasons of Blood Plus, Saya goes through this after meeting Haji, and starts to remember when she went berserk in Vietnam and older memories.
 * Villetta Nu of Code Geass goes through this when her battlefield injuries leave her amnesiac. One of the enemy, Kaname Ohgi, takes her in, conceals her past from her, and keeps her hidden from his comrades. Slowly, she grows infatuated with him...
 * In Deadman Wonderland, Nagi seems to be a perfectly friendly, polite and kind-hearted widower, whose only wish is to see his child outside of prison. Turns out that's not exactly the case.
 * Inverted and averted in Death Note: Protagonist Light gives up his memories of being the mass-murderer "Kira", then his mind wiped self tries to clear his name by joining a task force devoted to capturing Kira. Although he still keeps his intelligence and says that his thought patterns are similar to Kira's, his personality changes to that of a decent person rather than the self-righteous, prideful Well-Intentioned Extremist he was before that would be willing to use the Death Note (the most jarring is the difference in how he treats Misa). Even if he doesn't sympathise with Kira because he wants to clear his name, the personality change was the series' only notable headache.
 * In Elfen Lied, when Lucy loses her memories, she goes from being a violent mass murderer to an innocent, harmless (and slightly retarded) girl, Nyu.
 * After Greed is captured in Fullmetal Alchemist, he is given complete amnesia by his creator Father. When confronted by a former companion, Greed kills the companion which causes memories to start resurfacing. One of the images he sees is King Bradley (who killed his three closest companions) and Greed attacks King Bradley's house before running away.
 * In Gunnm (aka Battle Angel), Alita/Gally eventually discovers that she was a ruthless terrorist before her body was discovered in the Scrapyard at the beginning of the series. In fact, she's directly responsible for the Dystopia she'd been rebelling against.
 * Though he didn't exactly turn evil, Sho in Guyver had this happen in the infamous arc where . Notably, Sho was affected by this for some time: he built up a mental block about his powers that only subsided when his love of and duty towards Mizuki overruled his guilt.
 * In the Higurashi no Naku Koro ni manga, Keiichi falls asleep, and forgets he He wakes up quickly and sees the  This is not in the anime or sound novels, though.
 * One example that did occur in all adaptations is when in a later arc, Keiichi
 * Although he wasn't so much "Amnesiac" as
 * Kannazuki no Miko: This happening to Chikane is the reason for her Face Heel Turn.
 * In Magical Project S, Sasami's friend Misao has the split personality of Pixy Misa created by Rumia. Since she has no memories of being Pixy Misa, she's completely clueless. Pixy Misa seems to be aware of being Misao, though, and the series often plays this up for laughs, such as when Pixy Misa tricks Sasami into believing she's "kidnapped" Misao (by using a giant screen to cover her transformations, all the while Misao is completely confused as to what's going on).
 * Used and played with in Monster with two of the main characters and some interesting children's books.
 * In Naruto, nearly played straight with filler character Memna. Formerly a bandit, he became kindly and even heroic after losing his memories. However, the trope falls apart when it's revealed that he lost his memories during a Heel Face Turn.
 * Atori in Noein goes from Ax Crazy Psycho Electro to a mild, almost childlike guy after losing his memory.
 * In a later episode of Noir it appears that Kirika is being Brainwashed. The reality is that her self up to that point was the brainwashed self, and the ritual removes it. In the penultimate episode, Mireille fights not only the "true" Kirika, but attempts to get her "fake" version back.
 * Mara from Ah! My Goddess, despite being a demon, is shown to be extremely gentle and kind after she loses her memories. Unfortunately for the protagonists, she was holding Keiichi's sister hostage before she lost her memories, making it necessary for them to restore her memories.
 * In Scrapped Princess, Sim, a cute little amnesiac waif, is taken in by the main characters. She is later abducted by the Peacemakers, ancient humanlike machines out to kill the protagonists, and revealed to be one of them who had been uncompressed from her storage state erroneously. When she is fully uncompressed, she is called 'Cz', has the form of an adult and remembers her original function as the protagonists' enemy, though she retains her 'Sim' memories.
 * Akira in Eden of the East wakes up naked in the middle of Washington D.C. with a cell phone and no clue who he is or how he ended up there. As he tries to figure out what's going on, he at first gets the impression that he was a terrorist, but it's a bit more complicated than that...
 * In Fairy Tail, gets called out on for all his past crimes by Erza during the Oracion Seis arc when she's trying to prove she's not going to fall for his tricks again and buy his lie about having amnesia. Except he really does have amnesia, and since neither of them know that, and he's actually a good person at heart he's horrified to learn what kind of a person he was.
 * Teito in 07-Ghost
 * Neo Roanoke in Mobile Suit Gundam Seed Destiny comes down with a bad case of amnesiac dissonance once he's taken prisoner aboard the Archangel and meets Captain Murrue Ramius, who . Unfortunately, this and Neo's feelings about the unpleasant things he'd been doing prior to that point are given very little screen time.

Comic Books

 * There is an instance or two where The Joker, Batman's enemy from The DCU, loses his memories and becomes a regular family man. This self is always consumed by his madness returning.
 * The Marvel Universe character Falcon went through something like this in a Dork Age storyline where it was 'revealed' that he was actually a former street hustler named 'Snap' who had been brainwashed by the Red Skull to be the perfect new partner for Captain America, supposedly so that the Skull could then activate a post-hypnotic suggestion later to make him betray Cap.
 * Marvel loved this trope. Early on in Ultimate X-Men, Professor Xavier mindwiped Magneto and convinced him that he was a baseline human who taught handicapped children and was having a relationship with a human woman (with whom he eventually moved in). It worked...for a while.
 * For that matter, when a deaged, amnesiac Magneto turned up in the normal ''X-Men titles '90s, he spent a considerable amount of time worrying about his past actions and whether he was destined to repeat them. This was ultimately resolved when he was revealed to be a clone instead.
 * Another Marvel example is Taskmaster. It was recently revealed that his Photographic reflex ability comes at the cost of his personal memories. When he's able to remember who he was he regrets all the bad things he has done as Taskmaster. Sadly, in order to protect  Mercedes, he has to use his ability to its limit by combining every move he had learned along with copying the fighting style of the guy attacking them in order to defeat him, causing him to forget himself again.
 * Earth-2 Catwoman had been suffering from amnesia during her criminal career. When she recovered, she was willing to go to prison for her crimes. (Later, during a story where Batman sprang her from jail to help him, she revealed that she had made up the amnesia to make her Heel Face Turn plausible; in reality, she had wanted to quit.)
 * In 100 Bullets, various characters discover that they were formerly highly trained assassins known as Minutemen who were brainwashed into forgetting their work. As they are awakened to their real memories by various usages of an embedded code word, they must decide whether to return to their old agenda or walk away.
 * In Sonic the Comic, Super Sonic is haunted for a long time by recurring nightmares of a demonic creature destroying the world and saving him for last. Eventually, he discovers these are actually representations of his past destructive urges, remembering in full that he was once the evil, chaotic Super Sonic. This leads him to refuse to use his powers lest he become corrupted by them once more - indeed, each time he taps chaos energy or his inert powers, he reverts to his crazy self.

Fan Fic

 * In the Death Note fic by Quiet "The Art of Drowning", this trope is the catalyst of the fic's plot, where the main time line diverges from the original story when Light suddenly realizes that the detective L is actually his "murdered" childhood friend L Lawliet. This triggers his suppressed memories and an inner Battle for dominance Light vs Kira.
 * In the My Little Pony Friendship Is Magic fic Past Sins, Nightmare Moon is reborn as a filly as part of a botched spell by a cult seeking to resurrect her as a mare of her own. She regains some of her old memories, leading her to feel guilt and then loses it when she regains all of them as the same cult recast the spell on her to complete her.
 * In Ditzy Doo: Muffins, Ditzy starts to recover her memories from before she came to Ponyville, and freaks out when she thinks she may have been a mob enforcer who killed a Canterlot guard and his wife.

Film
"Stryker: You were always an animal, Wolverine. I just gave you claws."
 * Douglas Quaid, the central character in Total Recall, discovers that before he had his memories rewritten he was Hauser, The Dragon to the movie's Big Bad, and that he had been on a mission to destroy the people on whose side he had since come to fight. Or did he .... ?
 * The protagonist of The Long Kiss Goodnight, a former assassin which ended up as a housewife in a small city.
 * Regarding Henry, where Harrison Ford plays an Amoral Attorney, who gets shot and loses his memory. He's appalled at what a jerk he discovers he was.
 * In the Laurel and Hardy short "A Chump at Oxford", while our heroes are visiting Oxford University Stan gets hit on the head and becomes a snob with an English accent, much to Ollie's disgust. Not surprisingly he later gets hit on the head again and returns to his old self.
 * The title character in The Iron Giant loses his memory shortly after crashing on Earth (probably when he got electrocuted by the power station while trying to eat it), and is unaware that he is actually a Weapon of Mass Destruction until his built in self-defense protocols start getting activated. When he believes Hogarth is dead, the next army attack seems to undo the dent in his head and his full military programming comes back online (though he still reacts based on self-defense, targeting the greatest threat which is actively attacking him). When, he helps the Giant remember their time together and that he has a choice in his own actions.
 * In Overboard, Goldie Hawn plays a Rich Bitch who loses her memory after falling overboard her yacht. Kurt Russell plays an average joe handyman who convinces her that she is his wife (he's widowed) in order to get revenge for unpaid work on the yacht. The two characters fall in love and when Hawn's character eventually regains her memory she must decide whether to go back to her previous life or remain with her new family.
 * Notably, she doesn't automatically become nice when she gets amnesia. She's still pretty much a bitch until living a life where everything isn't handed to her teaches her some humility.
 * The fear of Amnesiac Dissonance drives the suspense in Unknown. Several kidnappers and their captives wake up in a vacant warehouse, having succumbed to an accidental gas leak that has caused temporary amnesia. They find clues that some of them are criminals, but don't know which of their own number are the bad guys, and need to figure it out before the rest of the kidnapping gang comes to collect their prisoner.
 * Seen in X 2 X Men United; Stryker claims that he and Wolverine were partners before Wolverine lost his memory.


 * Based on the prequel film,.
 * Happens in Resident Evil with
 * Played with in Dark City: J. Murdoch has no memories, and the only evidence he can find about his past points to him being a serial killer. He's horrified, and soon becomes convinced that it can't be true, that he isn't a killer. Turns out he's right, and the truth is even stranger:
 * Lieutenant Payton in Pandorum is honestly trying to remotely assist Bower in his attempt to restart the ship's reactor. However, when he finds out that he is really (he had hypersleep-induced amnesia), he instantly turns into a murderous nihilist.
 * 's character in Unknown (aka Unknown White Male) turns out to be a terrorist/mercenary-assassin.
 * The titular character in Angel Heart discovers that the evil murderer that he was hired to find was himself, and not only that, he also found out that he had had sex with his daughter.

Literature

 * In Dan Abnett's Gaunt's Ghosts novel Traitor General, is deeply indignant about his treatment by Imperial forces. When the mindlock on his memories, he realizes that he had been treated justly and deserved to die.
 * In Robert Ludlum's The Bourne Identity, the amnesiac David Webb comes to believe that he is professional contract killer Jason Bourne, which was in fact only a cover assigned to him by the CIA before the incident that caused his amnesia. When the Big Bad comes to realize that something of this nature is occurring, he begins setting Webb/Bourne up to reinforce this belief.
 * This is played quite differently in the movie adaptations of the Bourne novels; prior to his amnesia, Webb/Bourne had in fact been trained as an assassin, if a government-sponsored one. The amnesia works as something as a mental-reset button, as he'd been brainwashed into becoming the assassin. As a result, post-amnesia he is The Atoner.
 * The entire plotline of K.J.Parkers Scavenger Trilogy, although Poldarn quickly figures out that he probably won't like what he remembers.
 * The problem isn't just that he has issues with who he was before he lost his memories. It's also that the amnesia fades over time, giving him issues with what he did as an amnesiac.
 * PG Wodehouse's novel The Indiscretions of Archie does this for laughs: Archie befriends a man who has lost his memory during the war and, horrified, suspects that his name may be Lancelot.
 * At the beginning of John C. Wright's The Golden Age, Phaethon learns that he is suffering from Laser-Guided Amnesia and told he has committed horrible offenses. A Neptunian urges him to flee to have his personality repaired, pointing out that his self-chosen name shows that he is not by nature as acquiescent as he acts.
 * In the third book, The Golden Transcedence, Daphne reveals to Helion that so far from supporting the Horators' attempt to stop Phaethon, in his missing hour of life, he had pledged to support Phaethon.
 * Happens to Corwin at the opening of Roger Zelazny's The Book of Amber.
 * Pretty much the plot of Chasm City by Alastair Reynolds.
 * Happens in the EVE Online novel Empyrean Age: A high-ranking, slave-keeping Amarrian official suffers amnesia due to a botched assassination attempt. He is found by a Ragtag Bunch of Misfits, which includes Minmatar members, who naturally react to his presence with revulsion. While he eventually reassumes his position, he keeps the nice guy persona he developed during the story.
 * In a short story by Diana Wynne Jones, a young prince wakes up in a field staring into the eyes of a witch, who tells him perhaps this will help, and leaves. He struggles to survive in the nearby city, selling everything he has on him and eventually working for a living. Finally, he comes across some people who recognize him and take him home. Due to his complete amnesia of anything before, and the fact that he now understands how difficult other people have it, he's a much nicer person. Everyone who knew him before keeps complimenting him on his niceness in a way that's not quite complimentary. Even worse, his Arranged Marriage fiancee has the same eyes as the witch who cursed him, a fact he tries hard not to think about too much.
 * A somewhat similar situation comes up in Diana Wynne Jones's Castle in the Air, where it turns out that a character had been given amnesia and memories of a different identity to teach him a lesson.
 * Self-inflicted in John M. Ford's short story Erase/Record/Play, in which the scientists experimenting on prisoners in a concentration camp give everyone - victims, guards, and tormentors - the same experimental memory-wiping drug, and mix themselves into the general population to avoid punishment when the liberators come. They can't be coerced or tricked into revealing their guilt, because even they don't know if they're guilty.
 * In The Candy Shop War, Nate and his friends are given a Blank Slate—a magical food that will cause whoever eats it to lose all their memories and become, well, a Blank Slate—and are told to use it on a rival magician. They can't bring themselves to do it, but Nate holds on to the food anyway. But when it becomes apparent that there's no way to stop the main villainess from drinking from the Fountain of Youth and becomming an unstoppable Child Mage, he crumbles the slate into her goblet of magic water... thus turning her into a harmless and sweet-natured little girl.
 * In Evan Hunter's novel "Buddwing" a man wakes up in a park with no idea who he is. He creates a name for himself based on seeing a Budweiser truck and an airplane and goes searching for who he is and what has happened to him. At the end

Live Action TV

 * The Babylon 5 episode "Passing Through Gethsemane" centers around a mind-wiped Serial Killer who lives as  Upon discovering his past, he's aghast. How can he pray for forgiveness when he doesn't even know his sins? Ultimately, he decides the only way he can atone is   In an ironic Twist Ending,
 * In the episode Divided Loyalties Lyta Alexander arrives on Bablyon 5 to tell captain Sheridan that someone onboard the station is a sleeper agent and that only by sending a specific word into their minds can they find out who it is.
 * Buffy the Vampire Slayer: It's written into Angel's curse that every time he's subjected to a Heel Face Turn, he gets about 30 seconds of amnesia before the memories of his past evils return all at once, sending him into his usual guilt spiral.
 * Subverted in the case of Connor, who didn't get a full restore, but a vague remembrance like a dream. As the major impression is that they were very unpleasant, he seems happy enough with who he is now.
 * In the 2007 series of Doctor Who hides from  by transforming himself into a  and erasing his memory, becoming . His original memories are stored inside
 * This is similar to the anniversary special audio drama Master where the Master is given 10 years of an amnesia-induced normal life if the Doctor agrees to kill him at the end of it. Things get complicated to where the Master has to decide whether to become evil again for the right reasons, or to stay who he is for the wrong reasons.
 * Also happens in the audio drama The Holy Terror:.
 * Played for Laughs and Lampshade Hanging in an episode of Due South where Benton, in a state of amnesia, reacts with total bemusement to the other characters' explanations of what he is normally like, and the quirks that they have all by then gotten used to, like his living in an unfurnished apartment where he sleeps on the floor. ("Why am I living like this? Am I being punished?")
 * Inverted in Heroes, when
 * Later played straight when
 * In an episode of Hustle, The Mark discovered the con, then came down with Easy Amnesia. The team decided this was an opportunity to run the scam again without making the same mistakes, but when they saw how horrified he was at his own business practices they realised they were breaking The Code; conning an honest man. (It eventually transpired that )
 * This is the entire premise of Christina Applegate's show Samantha Who?
 * The Stargate SG-1 episode "Past and Present" had Daniel Jackson fall in love with an amnesiac whose previous self turns out to be pure evil. When she starts regaining her memory, she tries to kill herself but Daniel stops her and erases her memory permanently, which unfortunately erases her memories of him.
 * The Stargate Atlantis episode "Michael" features previously unknown Lieutenant Michael Kenmore
 * In the 1996 made-for-television movie Sweet Dreams Alison Sullivan, played by Tiffani-Amber Theissen, awakes from a coma with amnesia. She speaks to various acquaintances from her life to uncover her past, discovering that she had not previously been a nice person, and begins to realize that her amnesia is a result of someone's attempt to murder her because of her misdeeds. She foils them, and then decides to stay the nice new version of herself.
 * In the Red Dwarf episode "Back To Reality", the crew wake up from the virtual reality game they were playing, and discover that their real personalities are very different from the people they thought they were. Dave Lister, who likes to think he's a good guy who will usually do the right thing, discovers that he's really a brutal fascist officer; Arnold Rimmer, who thinks he's better than Lister, discovers that he's really Lister's less successful brother; Kryten, who thinks he'd never harm a human being, discovers that he's capable of murder; and the Cat, who defines his whole existence by his sense of style and good taste, discovers that he's really an awkward, buck-toothed, fashion-deficient Nerd. Subverted when
 * An episode of Criminal Minds had a serial killer attempting to escape police, only to fall several stories down and end up in a coma. He awakes years later, with no memory of his former life or his actions. Most people believe he's faking, but his amnesia is sincere... Until his memories begin returning..
 * One episode of Medium centers around a former serial killer whose modus operandi was to hire a prostitute, smother her with a pillow after having sex, and bury her in the desert. But one night his plan goes awry when the woman's pimp breaks into his house as part of a planned robbery, and the killer is shot in the head during the ensuing scuffle. When the prostitute visits him in the hospital, she finds that he has amnesia, and remembers nothing about his murders. Once he is discharged from the hospital, he continues his life minus the murders; the woman leaves her life of prostitution and eventually the two end up married. Despite learning all this from the former prostitute, Allison continues to pursue the issue so the bodies can be found. When pressed, the former killer seems to vaguely remember the murders, and it is implied that he leads the police to the bodies. It's never made clear when the memories began to come back, how many of them came back, or even if he ever truly forgot.
 * On Dollhouse, Echo gradually comes to realize that Caroline, the original personality in her body, wasn't such a good person, and is no longer sure if she wants her old memories back. This may have been a response to the audience finding Caroline, who was a radical member of an Animal Wrongs Group, to be a rather unsympathetic heroine.
 * Although, as Adelle notes, Caroline isn't evil---she's an idealist (which, Adelle also notes, can be worse). Echo is Not So Different from Caroline, but comes off more sympathetically.
 * An episode of The Outer Limits involved an amnesiac who is being helped by a woman he met. They are being chased by unknown persons. Every so often, he gets an injection of liquid that appears to hold his memories, remembering more and more each time. In the end, he is revealed to be the evil boss of the people chasing them and uses the same procedure to erase the woman's memories.
 * Happened to Divatox in the most infamous episode of Power Rangers Turbo, the one where the rangers get baked into a giant pizza. When she loses her memory, she also loses all piratical aspects of her nature, and becomes a mildly surly (but good natured) employee at a pizza place.
 * An unusual variation occurs in The Sarah Connor Chronicles episode "Allison from Palmdale." Cameron's processor begins to glitch due to damage sustained earlier in the series, and she loses her sense of "self." She also begins to recall memories of a girl named Allison, who looks exactly like her, who in reality was a resistance fighter that her appearance was modeled after and she interrogated for information. Cameron begins to think she actually is Allison, and begins to act like her, reciting memories of parts of her life and expressing human emotions. Its isn't until the end of the episode that she remembers who she really is and reverts back to her normal programming.
 * Averted in Kamen Rider Kiva. Wataru and Shizuka befriend a large, cheerful man who Does Not Know His Own Strength, nicknaming him "Dai-chan" ("Mr. Big", essentially). When he recovers his memories, it turns out that . Recovering his memories causes him to pretty much go back to the monster he was before, except for a rather weird deathbed conversion-type thing where, in his final appearances, he decides to do good deed in the hopes of getting into Heaven.
 * Another aversion is in Kamen Rider Decade in which Tsukasa is revealed to be, he takes it in stride once his memories return to him when speaking to Tsukikage.
 * Played straight though in Kamen Rider Double. After it's been revealed what family Phillip is a member of, he doesn't take it well.
 * The "Dead Head" episode of Human Target features a money launderer who contracts amnesia on his way to meeting Chance & the team for protection. This leaves them the job of protecting someone without knowing who he is, who's trying to kill him, or why.
 * The Shadow Line teases this with Jonah Gabriel, who is implied to have been a Dirty Cop before he lost his memory in contrast to the good cop he is afterwards.
 * The TV movie In The Shadow Of Evil is about a cop who develops amnesia while on the case of a serial killer whose pattern indicates he will kill again in a month. Towards the end of the month he has regained enough of his memory to realise he's investigating himself.

Tabletop RPG

 * While he is an arrogant Anti-Hero, Swan of Exalted should feel real glad that he has no memory of the former holder of his shard's life.
 * He seems to be aware of this on some level, judging by the opening comic to the White Treatise sourcebook (in which Arianna suggests finding out about their past lives, and he isn't really all that keen).
 * As of Scroll of Exalts' write-up of him, Word of God states that he remembers minor snippets of a past life, just not those particular moments.

Theater
"von Konigswald: Orange juice! I killed a man with Orange juice?"
 * Le voyageur sans bagage (Traveler without luggage) is a Jean Anouilh play about a thoughtful, peaceful man who lost his memory in World War I and spent years in a psychiatric institution, oblivious to his identity. When his true family comes to reclaim him, he discovers that their missing son was a violent, borderline sociopathic egotist. Soon, though, the evidence that this man was him is undeniable.
 * Happy Birthday, Wanda June by Kurt Vonnegut is a comic example of this trope. Major Sigfried von Koningswald, an evil Nazi sadist who, now dead and in heaven, is baffled by his previous actions. He struggles to explain them to the audience...or to himself.

Video Games
"Human Raziel: "You're a righteous fiend, aren't you?" Wraith Raziel: "Apparently I am...""
 * Soma Cruz from Castlevania Aria of Sorrow and its sequel Dawn of Sorrow is an Ordinary High School Student, except for the whole "being the Reincarnation of Dracula" thing—something he has to resist succumbing to when he "remembers."
 * Tales of Innocence invokes the reincarnation variation of the trope with every Avatar ingame. Luca, having been the great Asura, is constantly attacked by friends and foes from his old life. Meanwhile, both  go into brief Heroic BSOD when they  All the other party members also comply to the trope, to a slightly lesser extent.
 * In the PS2 game Disgaea 2: Cursed Memories: it is revealed that  really isn't the Big Bad. She had gotten tired of her role and reincarnated herself into the character who had thought she was. Whether she turns good or evil after recovering her memories depends on the character's actions up to that point.
 * Terra from Final Fantasy VI suffers from a variation from the start. Kefka had put a slave crown on her and used her powers for all sorts of casual slaughter with her being utterly oblivious about this. Once it comes off and people mention what she's done, she comes down with massively crippling guilt for a large part of the game. Combined with her fears of being less-than-human, she makes a very effective woobie.
 * Dissidia Final Fantasy mirrors this by having Terra learn that in a past cycle, she was brainwashed and forced to fight on the side of Chaos.
 * And Duodecim, the prequel, plays through that cycle, revealing that it was Vaan who helped snap her out of it.
 * Kuja in duodecim was this close to joining the good guys until Kefka ruined his plans and manipulated him into dying in a battle with Lightning. First thing when Kuja was revived in the next cycle, Kefka put it in his head that he loathed Zidane and wanted nothing more than to kill him
 * Ghost Trick spends a lot of time setting this up, displaying the seemingly nefarious doings of pre-death Sissel and making the protagonist wonder if he was really that bad of a person. Of course, the man in red is certainly a monster.
 * This happens with at the end of the chapter Smile in Killer7.
 * In Knights of the Old Republic, it turns out that  was actually Darth Revan prior to being mind-wiped by the Jedi. No matter whether Revan turns to the light or the dark side, the ex-Sith always ends up killing Darth Malak.
 * They do, however, at least give both choices a motive for doing so.
 * The Legacy of Kain series averts this trope, but only temporarily. The vampire-wraith Raziel discovers that he and his brothers used to be vampire-slaying priests. At first he embraces his former humanity, but upon traveling into the past, he discovers they were just as bad as, (if not worse) than, the vampires they hunted. Raziel renounces and kills his former self, setting the stage for his eventual resurrection as an amnesiac vampire.


 * This is the major plot twist in Lufia (Estopolis in Japan), and one of the earliest examples of the trope in a game plot.
 * Much of Zero's story in the Mega Man X games comes from villains attempting to resurrect his "true" personality as a ruthless killing machine; there has been much fan speculation that Zero was responsible for the deaths of the original cast of the Mega Man games while in this state.
 * The aforementioned theory was Jossed fairly recently; Word of God stated that Zero was not responsible in any way, shape, or form for whatever happened to the cast of the original Mega Man games, even as his "original" self.
 * Zero suffers this again in the transition between the X and Mega Man Zero series. While he stays a hero in between both series, his memory was lost during hibernation, including one crucial detail:
 * In Persona 3, 's only reason for being is to serve as the vessel by which Nyx will destroy the world. In a subversion, despite the fact that it is against his will, he accepts it as inevitable and gives the Main Character the option of killing him (and erasing SEES' memories of the Dark Hour) to spare them the agony of having to watch the Fall unfold before their very eyes.
 * The protagonist of Planescape: Torment has lost his memory multiple times. He slowly, steadily recovers memories from several past stages, each with their own moral codes (or lack thereof). There's an especially well-written scene, if you've taken the good path to that point, where he recalls a particularly heinous moment from his Manipulative Bastard stage and breaks down in horror at his past selfishness.
 * It's also revealed, if the right actions are taken, that In fact, that turns out to be the reason for the immortality thing:
 * Alex Mercer of Prototype hunts down and kills dozens of people and killing several thousand in the crossfire in a combination of a Roaring Rampage of Revenge and investigation of the Infection's release and his own transformation, only to find out that
 * In La Pucelle Tactics, two of the characters have lost their memories two years ago. Both of them are now demon hunters on the side of light. Turns out,
 * Shining Force 2: When the young boy Oddler is left blind and amnesia-stricken by battle wounds, The Hero takes him into his party, protecting the youth from devils that have been hunting him for some reason. Near the end of the game, though, the truth comes out: Oddler is Odd Eye, the most powerful general in the Big Bad's devil army! Though he still remembers traveling with The Hero, his eyes have been opened and his duty is clear. Now they must fight.
 * The major plot twist in Silent Hill 2.
 * In Snatcher, protagonist Gillian Seed is an amnesiac police agent who is assigned to take out the identity-stealing androids.
 * Cammy from the Street Fighter series joins the good-guy Delta Red faction after her Laser-Guided Amnesia erases all memory of the fact that she was created to be the next body of the Big Bad Bison.
 * In Super Robot Wars Advance, Amnesiac Axel Almer, who serves a stint as protagonist, is actually The Dragon of the Big Bad and the Mad Scientist's lover. He comes to grips with this and proceeds to betray his former comrades, who thought he was just being a really awesome spy. Not a spoiler, as the other protagonist's route warns you of this immediately.
 * This is also the stint of Cobray Gordon in Super Robot Wars Alpha 3. Certain event causes him to lose his memories and join the team. This gets more complicated as he's under the threat of.
 * Mai Kobayashi is a double case of this. As Levi Torah, she tried to resist the Judecca's control, pleading for someone to rescue her. Then, when the Alpha Numbers/Original Generations save her, she forgets all about the Ze Balmary, only for memories of Levi to come back and try to take control of her again.
 * Amnesia the Dark Descent: One of the true horrors of the game is realizing what a depraved monster the player character Daniel was before he gave himself amnesia. No wonder he chose to forget, even though it would make killing Alexander a lot easier if he knew what he was supposed to do and why.
 * In Twisted Metal Black, Roadkill's driver is an amnesiac who came to in the wreckage of a gangland bombing, and finds himself covered with one of the gang's tattoos. He enters the tournament in the hopes that Calypso will restore his memory. In his ending,
 * Another character in the game, Preacher, believes himself to be possessed by a demon that slaughtered his congregation during an exorcism gone bad; he wants Calypso's help to clear his name and reveal the truth to everyone so he can fight the demon. Calypso delivers the truth, but it's not what Preacher wanted to know... that there was no demon, the "exorcism" was just a baptism, and Preacher is a psychotic multiple-murderer. He doesn't take it well.
 * The white chamber has Arthur reveal to Sarah that she was the one who murdered the entire crew.
 * Cave Story subverts this. Several NPCs recognize Quote as "a soldier from the surface", or make references to squads of war robots that came to the island ten years ago and massacred the Mimigas. The obvious conclusion for the player (and several in-game characters) is that Quote was one of those killer robots—rather unsettling since Quote is currently trying to save the remaining Mimigas. But, if you complete the sidequest to save Curly Brace and restore her memories, then she remembers that Quote was comrade-in-arms ten years ago. And unlike all the other combat robots, they hadn't fought the Mimigas; their mission had been to destroy the Demon Crown.
 * World of Warcraft: This occurs during the starter quests for the Death Knight class. You, the Death Knight player, start the game following orders from Lich King & pals. You run about destroying a town, slaughtering its townsfolk and torturing its guards. Then you're given an order to kill a hostage NPC, but when you confront him/her, he/she turns out to be an old friend of yours who reminds you of your past before you became a pawn of the Lich King—when you were a hero. After you finish the NPC off, you begin your transformation into an Anti-Hero.
 * Played with strangely in Trauma Team. CR-S01 is a surgeon committed to saving lives who was seemingly a bioterrorist behind an attack on Cumberland College prior to his amnesia. However, despite the fact that he can't remember how he did it or why, he's fully aware of this fact—it's actually his knowledge of what he might have done before, absent any of the memories that drove him to it, that motivates his Heel Face Turn..
 * In Digital Devil Saga, Serph learns that as Serph Sheffield, he singlehandedly not only caused the suffering of countless children as well as mankind, but also manipulated Sara to thinking he is the Good Prince vying for her affection while Heat is seen as the Evil Prince.
 * Side note: There was no amnesia involved, as Serph and Serph Sheffield are not the same individual. The Serph you play as was originally an AI that Sera created her virtual play world (which later became The Junkyard of the first game), and his personality was based on Sera's perceptions of Serph Sheffield. Incidenlty, this is also the reason why Serph is a Heroic Mime, his lack of personality reflects Sera's lack of understanding of who the real Serph Sheffield really was.
 * Initially, Overlord doesn't even provide a framework for this trope—the game begins with your being disinterred and declared the Overlord, and apart from indications that you were quite evil your past is treated as unimportant. You are informed, however, that the seven heroes who oppose you previously defeated not you, but "your predecessor."
 * In I Have No Mouth, and I Must Scream, one of the main playing characters is an elderly German scientist called Nimdok who has a failing memory. The Big Bad of the game, mad and omnipotent supercomputer AM, sends him to confront his past... where it is revealed that he Apart from that, Nimdok is a kind old man who is horrified by what he discovers in the camp and feels sorry for the detainees here.

Visual Novels

 * Tanya, who is the android love interest from the science fiction visual novel Bionic Heart, learns that, which explains why she has century-old memories. Unsurprisingly, she has a Heroic BSOD from the revelation.

Web Comics

 * Trace from Twokinds. Interesting in that the only person not aware of his past is Trace, nearly everyone else is well aware of who he is/was and openly terrified of him. It's gotten to the point that Trace has decided that he's better off not knowing who he was.
 * The eponymous character of Zap
 * MSF High: Students at MSF High can surpress painful memories as part of their 'second chance'. If these memories are discovered, this can occur.
 * In Fleep, Jimmy is rather horrified to infer that he used to be a terrorist, and that the building he's trapped in was collapsed by a bomb he set off. What's interesting is that he never actually remembers any of this—so he ends up inferring what he did well before he figures out why he did it.
 * Bob and George: Claimed and subverted.
 * Jack of Jack was a genocidal dictator in life but when he died and became the Grim Reaper and Anthropomorphic Personification of Wrath his memories were erased. Now, he's a pretty nice guy all things considered.
 * Hector: Animated Armor and Minion with an F In Evil turned good from A Modest Destiny, were at some point "resurrected" by the resident vampire lord, Fluffy. The only thing he can remember is that it was his own sister that killed him, and she is also a vampire. It is later revealed that.
 * Parodied in Chainsawsuit.
 * In Sinfest, Lil Evil drank from Lethe and fears this.. (with reason!)

Web Original

 * In The Gamers Alliance, Ronove recovers his memories during the siege of Vanna and remembers that he used to be a Dreadlord of one of the demon hordes. After this realization he leaves his human friends behind, retakes his former position in the horde, starts acting like a seemingly cruel Manipulative Bastard as most demons do, but he also still seems to harbor some feelings for his former companions in the Alliance who he is now forced to oppose. He shows some of his quirky habits from his amnesiac cuckoolander days (such as his love for cake and sand gnome legs) but it's now mixed with his former dutiful yet cruelly efficient persona which has evolved into something more manipulative and vengeful because he's now fully aware of who betrayed him and caused his amnesia in the first place. He even keeps lampshading his sudden personality change every now and then, further cementing the fact that the different sides of Ronove coexist and that he hasn't set aside everything from his amnesiac days.

Western Animation

 * In Legion of Super Heroes animated series, there are two ShapeShifters, one on each side, who undergo processes to forget themselves and become one of the other side's members in order to gain intelligence. Chameleon Boy before finally remembering who he is. And  ends up revealing he's actually  in the process and is shocked to discover he'd forgotten who he really was.
 * In an episode of Lilo & Stitch: The Animated Series, the experiment of the week erases peoples' memories. Lilo, Stitch, and Gantu all get zapped and try to reassemble their pasts together; they don't come up with much that's conclusive about Lilo or Stitch, but reckon Gantu must have been a cop. So they become very good friends, and don't worry all that much about their memories-until Lilo learns that there's a way to reverse the effect, and learns the codeword. Gantu, meanwhile, has learned that he was not a very nice guy. He's quite vehement that he doesn't want to go back to being a jerk-until Lilo says the codeword anyway, and he remembers the one bit of context his amnesiac self didn't, viz. he loves being a jerk.
 * In a second-season episode of Superman: The Animated Series, villainous cyborg Metallo turns up on a volcanic island with no memory of himself; he saves a young girl's life and does other good deeds, but eventually he remembers his battle with Superman and turns evil again.
 * In Transformers: Beast Machines (the sequel to Beast Wars), Megatron had brainwashed two of the Maximals and given them entirely new identities. Upon recovery, Silverbolt became The Atoner, and Rhinox decided to stay evil and competed with Megatron.
 * Though it must be said that (possibly because the writers realized how much they'd pissed off the fandom), when Rhinox dies at the beginning of season 2, it's implied that he regrets his actions and is allowed to peacefully move on because his heroism in Beast Wars still outweighed his more recent actions.
 * Also from Transformers, the character Flip Sides from both G1 and Transformers Animated, is a decepticon who has a double-life as an Autobot—in G1 she's a teacher, in Animated she's a pop star. The catch is, while she's an autobot, she does not know or realize that she is a decepticon spy. Talk about conflicting moralities.
 * In an episode of the Aladdin TV series, Jasmine lost her memory due to a magic rose and Abis Mal convinced her that she was evil. This backfired when Jasmine became a Dark Action Girl and decided the idiotic Abis Mal was beneath her.
 * In the Generator Rex episode "Rabble", Rex is hit hard with this as he meets up with three old friends of his - who he doesn't remember at all - who are stuck working for a crime boss named Quarry. It turns out that in a former life,, and Quarry uses this fact to turn Rex's old friends against him.
 * An antiheroic version: in one episode of DuckTales, Scrooge lost his memory and was lost on the streets without a penny to his name. Eventually he moved in and began a romance with an extremely working class single mother, and when she told him about Scrooge McDuck's employment practices reinvented himself as a socialist crusader against a man he saw as a Corrupt Corporate Executive. At the end of the episode he regained his memories and had no recollection of what happened, but the protest he unknowingly began forced him to improve worker rights.
 * In an episode of Young Justice, the team wakes up in the Biyalian desert with their memories of the past six months erased. This turns Superboy into a mindless berserker (he's not even six months old), Kid Flash and Artemis start flirting with each other and even hold hands right before their memories are restored, and Artemis believes she is there because her father wants her to kill Kid Flash.