Faking Amnesia

When a character pretends to suffer from amnesia, or some other kind of memory loss.

The motivation for doing this varies: someone who has recently acted like a jackass or gone through an embarrassing situation may simply not want to relive it with others. A victim of Mind Control may seek an excuse to not talk about any pain they may have caused friends and family. A more nefarious character may fake memory loss to remove suspicion from themselves for a crime they committed, or to refrain from divulging sensitive information to their enemies.

The amount of memory a character may claim to have lost can range from just a few days, months, or even entire lifetimes. This can often depend on how vital it is to keep quiet about the incidents in question.

Faking Amnesia is usually more believable to others when the individual has recently gone through some kind of trauma, like a blow to the head or Demonic Possession. A suspicious character may attempt to trick the faux amnesiac into mentioning something about the events to prove that they remember it after all. If the faker accidentally slips up and gives themselves away, they may make a big show about their "miraculous recovery."

This can sometimes overlap with Fake Defector, if the character is faking memory loss for the sake of temporarily joining their enemies.

A sub trope of Obfuscating Disability. Compare Memory Gambit, in which a character arranges to actually have their memories removed to further their plans. Not to be confused with Amnesiac Liar, in which an individual who truly has amnesia is fooled into believing a falsehood they told before acquiring the condition.

Anime & Manga

 * In the Alien-esque Hentai Alien From The Darkness, the lone survivor of a derelict ship pretends to have amnesia, and is thus unable to tell her rescuers what happened to the rest of her crew-mates. This is all to hide the fact that she is in fact the host to the alien being that killed them all.
 * Inverted in To Aru Majutsu no Index.  loses his memory but passes it off as a joke so Index doesn't feel bad.
 * The water fairy Athena Glory in Aria does this as a prank to her student, Alice.
 * In the second series of Code Geass, Lelouch adds this to part of his masquerade early on in order to throw off suspicion that he has regained his memories.
 * In episode 26 of Hayate the Combat Butler, after a fight with some baddies, Hayate ends up with a blow to the head, rendering him unconscious. Ayumu, being there when it happened helped Hayate tend to his wounds. When Hayate woke up, Ayumu then asks whether he likes her or not. Hayate then ends up faking amnesia in order to avoid answering the question. Hilarity Ensues.
 * In an episode of Ookami-san, Ryoko suffers from actual amnesia, where she thinks she's thirteen. When she later get's better, she pretends not to remember the entire day due to being embarrassed. Ringo catches her when she remembers eating.

Comic Books

 * In the Marvel comic Agent X, The Taskmaster accuses Alex Hayden of being Wade Wilson pulling this trick.

Film

 * While You Were Sleeping plays with this: Peter Gallagher's character, upon waking up from a coma, doesn't remember his fiancée (because they really aren't engaged, his family just thinks they are), so his family assumes that he's amnesiac. He figures out there's been some sort of mix-up, but he continues playing along with the amnesia story to avoid upsetting the family too much.

Literature

 * In Mass Effect: Retribution, when a rescue squad recovers a kidnapped character and asks for his name, he is unable to answer and claims that amnesia is the cause.
 * The Titular character from the Robin McKinley novel Sunshine pretends she has PTSD that made her forget or block her memories after escaping from being held captive by vampires. Mostly she does have PTSD but she hadn't forgotten anything, she just didn't want to talk about it or explain A) why she saved a vampire and B) how she saved a vampire. That is to say by using her magic that she hadn't used since childhood to make it so a certain vampire could walk under sunlight which everyone agrees is impossible
 * The titular Papillon feigns having amnesia after being caught receiving contraband coconuts and cigarettes while in solitary confinement. The warden is frustrated by the inability to get a name and other details from Papillon and orders him to finish the final four months of his sentence without a dinner meal. Despite nearly dying of malnourishment, Papillon remembers to continue the game upon his release and "mistakes" the end of his solitary time as a pardon from the Penal Colony altogether.
 * Bobby Pendragon, from The Pendragon Adventure, feigns amnesia to get the Tribunal of Rayne to trust him.

Live Action TV
"Giles: "I've been reading up on my animal possession and I cannot find anything anywhere about memory loss afterward." Xander: "Did you tell them that?" Giles: "Your secret dies with me." Xander: "Shoot me, stuff me, mount me.""
 * Xander pulls this in the Buffy the Vampire Slayer episode "The Pack", after being possessed by the spirit of a hyena. After Buffy and Willow save him, he tells them that he can't remember a thing and hopes he didn't do anything "too embarrassing". Giles, however, sees right through it.


 * In a late-season arc of Wonderfalls, Heidi Gotts gets bumped on the head and decides to fake amnesia because so many people think that's exactly how amnesia works.
 * Used by Mrs. Slocomb in a later episode of Are You Being Served when she pretended to have forgotten everything since early childhood and spent the majority of the episode acting like a schoolgirl. The ordeal was a ploy to scare the management with a possible lawsuit.
 * In the Sentai show Kousoku Sentai Turboranger, Pink Turbo decides to fake memory loss to join the bad guys after taking a blow to the head in a battle, in a gambit to acquire an antitode for the poisoned Blue Turbo.
 * Supernatural: Dean fakes a case of Death Amnesia after being pulled out of hell by Castiel.
 * Inverted in an episode of Human Target. A client who has amnesia takes part in a sting to trick the bad guys by pretending not to have amnesia. To do this he has to convince them that he was faking it. It makes sense in context.

Newspaper Comics

 * Calvin and Hobbes: Calvin once tried this as an excuse for his terrible grades. His dad wasn't fooled.

Video Games

 * In Final Fantasy XIII, Vanille pretends that she's forgotten a substantial plot-relevant swath of memory in order to avoid having to share her Dark and Troubled Past (and its ramifications for their current situation) with the rest of the party. Her partner Fang, who really has forgotten, eventually tricks her into admitting it by pretending that she's also been faking her own amnesia.
 * At the end of Sly Cooper 3 Sly pretends to have amnesia in order to get close to Carmelita Fox (and avoid arrest). She tells him that he's her partner.

Webcomics

 * Played for laughs in Skin Horse: when Animal Control shows up to capture Sweetheart, Unity panics and feigns amnesia. She's apparently done this before.

Western Animation

 * In Hey Arnold!, Helga pretends to have amnesia. She did originally have amnesia, but recovered from it in the morning. Her mother told her that Arnold took care of her that day, which prompted her to fake it so he would continue to take care of her.