Living Memory

"Picard: Guinan, what are you doing here? ...I thought you were on board the Enterprise. Guinan: I am. I'm also here. ...Think of me as an echo of the person you know. A part of herself she left behind."

- Star Trek: Generations

The flesh is weak compared to the mind, heart and Soul, especially when in the throes of passionate emotion. Some places are especially malleable to psychic phenomena. Combine the two and you have the Living Memory, an echo of a person who is either still alive or who has definitively gone on to a final reward (or punishment).

The Living Memory is a very strange "being" and similar to ghosts in a lot of ways. Physically they're usually intangible (though Your Mind Makes It Real can make them dangerous regardless), but some are in physical (though probably non-human) bodies. They may be fully sapient and can be reasoned with, a chunk of memories with a bit of personality, or just vinyl records on an endless loop. What they all have in common is that they are not the real deal, the original, just an eerie simulacrum... and some even realize it.

When characters encounter a living memory, it's usually a highly emotional encounter. The Living Memory may distress the character emotionally, try to attack them... or offer encouragement and absolution for past sins. Like we said, Living Memories are strange.

This trope has a few variants.
 * The character has a piece of their soul split off and live haunt a person or location. This is especially common if the character "removed their dark side", in which case their Heartless will torment loved ones.
 * The Living memory is inside another character's head due to side effects from a Mental Fusion. A good chunk of the Split Personality tropes may apply, for good and ill.
 * There's no soul or anything of the like involved, the place itself is a Genius Loci and is using the psychic/spiritual equivalent of a plaster mold of the Living Memory's original as a marionette, constantly replaying past events.
 * Due to Time Travel related shenanigans, a long dead character can still make the Special Guest Star spot without actually coming back to life.
 * The Virtual Ghost is an AI construct with the personality and memories of the character, or a (near) exact copy via Brain Uploading. NOTE: If the original it's based on is dead, then it's a Virtual Ghost and the example should go there.

Anime and Manga

 * Kikyo in Inuyasha, she Came Back Wrong from the attempted resurrection since Kagome wouldn't give up her whole soul, so while the Kikyo golem does have (most? all?) of her memories, she only has a fraction of her original soul, the part that carried all the dark emotions about Inuyasha's "betrayal". She's not psycho, but she's not really the original either.
 * Mononoke: the eponymous mononoke are spirits which fused with strong human feelings, and in at least one case, with the memory one person had of an other one.
 * Seems to appear as well in Boogiepop Phantom, though given the amount of Mind Screw involved, it's difficult to assert with certainty.
 * The magical hologram of Queen Serenity on the moon in Sailor Moon.
 * Naruto meets  thanks to a form of this.
 * In Higurashi no Naku Koro ni, one of the manga- (and later, DS-) only Yoigoshi-hen takes place twenty years after the . Throughout the arc, various echoes of the main characters appear, showing varying levels of self-awareness, from Keiichi and Rena, who really looked to be nothing more than an echo of the memory of them racing to school, to, who apparently was not only self-aware, but actually . She may have actually been closer to your traditional ghost.
 * Umineko no Naku Koro ni has, at one point,  speaking to
 * Bakura places a piece of his soul inside the Millennium Puzzle, allowing him to follow the rest of the cast in a rare villainous example played straight. This splits off into Epileptic Trees when you learn that
 * In D.Gray-man, the Noah clan survives by passing their "memories" to a new host every time they are killed. While only Wisely and the Millennium Earl fully recall the past 7,000 years, the memories do tend to cause emotional reactions to things that range from feeling recognition of the Noah's original name to crying when a Noah dies to urges to kill Exorcists while in their presence, not to mention causing them to...see things in mirrors. This is made for a stronger trope when
 * In Soul Eater, Stein gets a shadow of Medusa in his head, who taunts him about him getting mad.

Comic Books

 * Barry Allen's fondness for time travel made it possible for him to appear several times between his death and resurrection.
 * For a while, Rogue, who had wiped out all of Mrs Marvel's memories, had her talking to her in her head, and sometimes trying to take control.
 * Still in X-Men, Xavier had a copy of Magneto in his head after mind-wiping him. It later became Onslaught.
 * In Empowered, Mindf**k psychically left one to Sistah Spooky,

Fan Works

 * In the distant Backstory of The Games We Play by Ryuugi, the being known as Keter does this as one of his backup plans before his final battle with his brother Malkuth. Thousands of years later, after his mindwipe and death at the hands of Malkuth, Keter's reincarnation  finally fights his way to the facility where his Living Memory resides and gets back enough of what he lost to carry on his fight against a diminished but still terrifyingly powerful Malkuth.

Film

 * Mal in Inception is literally Cobb's memory of his dead wife which has taken on a life of its own (her own?) in his dreams and any other dreams he enters. Said life generally involves sabotaging whatever Cobb's trying to do.
 * In Star Trek Generations, an echo of Guinan is present in the Nexus, and helps Picard find Kirk so they can stop Soran from destroying an inhabited planet so he can get back to the Nexus.

Literature

 * Tom Riddle's (Voldemort's) journal in Harry Potter and the Chamber of Secrets contains one of these. It's eventually revealed this is because it's a Horcrux and thus contains a piece of Voldemort's soul. The other Horcruxes contain smaller pieces and as such don't have personalities of their own, but do manage to act as Doom Artifacts.
 * Another example are
 * Not to forget all the portraits in Hogwarts, especially the ones of all the previous Headmasters, which act like some magical equivalent of Virtual Ghosts.
 * Not a character but still effectively this trope, in the Malazan Book of the Fallen the character Osseric is pulled in the a living memory of the Raraku desert by his father. The memory goes so far back into prehistoric times back to when Raraku was a lush swamp.
 * In Star Wars Expanded Universe, the Jedi holocrons serve such a purpose, allowing long-dead masters to share their wisdom.
 * Not quite; it's unclear what the projections really are, beyond being able to converse with people.
 * Ghosts in The Dresden Files are defined as echoes of a person's dying moments—they don't know they're dead because they can't realize they're dead. Harry himself gets an eyeful of this in Blood Rites when.
 * A Tale of Time City by Diana Wynne Jones has the Time Ghosts, which daily re-enact emotionally-charged moments from the City's history. Due to the timey-wimey involved in the City's construction, this includes the parts of the City's history that haven't actually occurred yet.
 * In Eon, by Greg Bear, Hexamon citizens can create "partials", which are (usually shallow) copies of a personality that can act independently, for use in dangerous situations or if a person is simply not available for some reason, and which can be re-integrated into the original person's memory once their task is complete. Partials are usually aware of their nature, but aren't bothered by it (presumably because the personality they come from isn't). It's considered mildly impolite to send one when you were expected to turn up in person. Also, once a citizen has used both of their state-allocated physical incarnations, they're stored as a Virtual Ghost in the City Memory, where they can still communicate with other people by digital means (and be reincarnated again if there's ever a need).
 * Robert Bakker is this through his former apprentice inhaling his dying breath.
 * Solaris revolves around these, created by an intelligent ocean on an alien planet. Each represents someone that a specific human astronaut felt guilt towards—a child, a lover, and so on. Killing or otherwise disposing of them results in the creation of another one, which has no memory of the first one's fate.

Live Action TV

 * There were a few ghosts on Buffy who were like this - the ones that made Buffy & Riley have lots of sex.
 * Those weren't actually ghosts, because no one died there. They were just Living Memories.
 * Doctor Who has had a few of these. In the new series, Steven Moffat absolutely loves this trope, especially with Creepy Child characters.
 * "Harvey", the mental clone of Scorpius inside Crichton's head (and Crichton's clone in Scorpius's head) in Farscape.
 * In Fringe, the "mind meld" Olive and Tom go through left traces of his memories and personality in her mind, which would occasionally surface and offer her useful information.
 * From a slightly different genre: the episode "Nothing Good Happens After 2 A.M." of How I Met Your Mother has Ted see and talk with his own subconscious in the form of his long-distance girlfriend.
 * Also from Star Trek: The Next Generation, not sure how many of these count.
 * Lt. Barkley has a bizarre hobby of creating holodeck parodies of his coworkers. On Star Trek: Voyager, the ship's doctor does this as well.
 * In Star Trek: The Next Generation episode "Skin of Evil", Armus is the cast off evil of a race that has Ascended to A Higher Plane of Existence. As such, he is basically Made of Evil and stuck haunting his planet.
 * In the Star Trek universe Vulcans can store their 'katra', which is a cross between mind, soul, and mystical technobabble, and one can communicate with them, although they do slowly fade.
 * The Stone Tape - paranormal television play whose key idea is that suitably traumatic events will be recorded and repeated by the environment witnessing it.

Real Life

 * Records of the thoughts of real people long dead are the closest thing we have to it.

Tabletop RPG

 * Phantoms in Dungeons and Dragons before 3rd Edition are the soulless shells of creatures who died hideous or surprising deaths. They almost always recreate images of their death or what they were thinking most about when they died, like a 3-dimensional movie, at the same place, over and over. Variant phantoms may be sounds or smells. Technically "monsters", but without a rhyme or reason to their existence beyond accidentally scaring or warning a passer-by, and nearly indestructible (dispelled only via remove curse spell).

Video Games

 * Thanks to all the Time Travel and Dimensional contorting, by the end of Chrono Cross Serge and co. run into three ghostly doubles of the main trio from Chrono Trigger.
 * ...though for some reason they all appear to be significantly younger than they were in Trigger, which has led some to speculate that they may not actually be related to the cast of Trigger at all beyond their visages.
 * Kingdom Hearts:
 * Pretty much the entire supporting cast of Kingdom Hearts Chain of Memories are literal living memories of Sora's who are playing out (and being deleted) via Naminé's powers. Of special interest is, a creation of Vexen's who is identical to (albeit with more access to dark powers) and survives the end of the story in a gag (manga exclusive) ending.
 * In Kingdom Hearts 358 Days Over 2,
 * The above picture is aptly named "Memory of Alessa", a boss in Silent Hill 3. She tries to kill Heather, who is basically her reincarnation, in order to help her avoid the pain and horror of birthing an Eldritch Abomination.
 * Also,  in Silent Hill: Shattered Memories is (arguably) one of these.
 * In the first 4 .Hack games, scenes from the anime series .hack//Sign can be witnessed by visiting the frequent hangout, Hidden Forbidden Holy Ground, at certain points in the storyline. They're described in a similar manner to Living Memory. At the end of the game, will join the party. They are noticeably out of place chronologically in their behavior, and players familiar with other aspects of the .Hack Universe will know there's no possible way it's the real versions, who are still alive but simply not playing The World.
 * It can also be seen in the G.U. series with Azure Kite, Balmung, and Orca, who are recreated versions of heroes from the first series integrated into the system to find bugs and glitches. They lack personality of the originals, however.
 * In Final Fantasy X, the pyreflies create this sort of effect on the Farplane.
 * It's not entirely clear whether these are the actual ghosts or what exactly. They don't talk and just kind of stand there. Only the dead (but not the Unsent) appear on the Farplane (Tidus is able to see his mom but not his dad when they first visit in the game).
 * Also, In Dirge of Cerberus, Lucretia's memories are stored as data inside Shelke.
 * Most smart AIs in Halo are created from the brains of dead people (as the process usually destroys the brain), but Cortana is the product of a cloned mind rather than a dead one. She and her creator, Dr. Halsey, often share many of the same attributes and opinions, especially regarding the Master Chief, John-117.
 * Forerunner AI was copied off the mind of.
 * In World of Warcraft WOTLK there is an encounter during the 5-man instance Trial of the Champion where you are up against Argent Confessor Paletress, who will summon one of various ghost-like “memories” of previous foes the player characters have (or should have) defeated in the past, who must now be faced once again. These memories include famous antagonists such as, Edwin Van Cleef, Lady Vashj, Onyxia, Hogger, Archimonde, and Illidan Stormrage, among several others who have a chance to spawn. It also may be worth noting that the flavor text of the spell Confess, which Paletress uses to summon them, states that it forces the target to confess their darkest memories, implying that the spell draws from the memories of the PC to summon a Living Memory of one of their toughest foes, so it probably qualifies for this trope. Suffice to say, as a 5-man instance these memories are not nearly as menacing as their living counterparts once were at the time of their original defeat.
 * In Solatorobo, end up as this in a DLC quest. Though they died in the main story,  they are eventually revealed to still be "alive" in Red's mind.

Web Original

 * The Red vs. Blue Recollections trilogy focuses on the Alpha AI, a smart AI created from the brain of the Director of Project Freelancer, in the same vein as those featured in Halo (see above example). Because of the various experiments in torture performed on it, the Alpha was forced to separate its worst memories from itself, creating yet another AI that contains all of the Director's and the Alpha's most anguished memories. Meanwhile, the Alpha (who caused Identity Amnesia through its actions) ended up reliving much of the same life events (read: failures, most notably the frustration generated by pursuing a lost love) that defined the Director's life. The final series in the trilogy, Revelation, reveals that