History Main / AmnesiaLoop

* Done in the ''ComicBook/AstroCity'' story "Her Dark Plastic Roots". Beautie, a SuperheroRobot based on a fashion doll, is unsatisfied because she doesn't know her own origins, so she begins to investigate the matter. Beautie eventually discovers she was created by Elaine Girbachs, the daughter of [[GadgeteerGenius Dr. Gearbox]], but he denounces Beautie because he believed engineering and math aren't fields for girls. Ashamed, Elaine tearfully ordered Beautie to leave and [[ExactWords forget forever]]. When Beautie confronts Elaine in the present day, she orders Beautie to leave again... and it turns out that this happens every few years as Beautie's directive weakens until she re-visits Elaine again and again and again.

* Beautie in the ''ComicBook/AstroCity'' story "Her Dark Plastic Roots" is a life-size "Beautie Doll" (inspired by {{Franchise/Barbie}}) who is unsatisfied with her life because she doesn't know her own history. She investigates and discovers she was created by a super-villain's then-eight-year-old daughter. When she confronts her creator, who is now in her forties, her creator resets her memory so that she doesn't remember her investigation, as she has done every few years as Beautie repeats her investigation. Beautie's friend and teammate MPH tells her to think about it next time, because Beautie deserves better.

** [[Recap/DoctorWhoS33ShortTheInforarium "The Inforarium"]]: The Doctor gets a guard at the titular LibraryOfBabel stuck in one because he's left a memory-proof recording, so the guard forgets about it every time he looks away. It's not permanent, though.

* In an episode of ''Series/StarTrekTheNextGeneration'', this trope's played with as the crew apparently encounters an unstable wormhole and moves on, only to start finding clues of a missing time period that lead them back to that anomaly for answers. It turns out that they investigated the anomaly before and uncovered a group of xenophobic {{Sufficiently Advanced Alien}}s who'd wiped their memories to keep their existence a secret, which created the missing time period. Once the truth's revealed, the crew redoubles its efforts to cover up the events all over again so they won't go through yet another loop, since, if they come back a third time, they almost surely ''will'' get killed by the increasingly annoyed aliens.
* In one episode of ''Series/StarTrekVoyager'', the Doctor has to choose between two patients to operate on because he can only save one. He chooses the main character rather than the RedShirt, then has a HeroicBSOD over what he thinks was a SadisticChoice. To cure him of this, the crew secretly erase his memories of the operation -- except the Doctor keeps stumbling upon the evidence, and going into HeroicBSOD all over again. Eventually the crew realizes that they'll just have to leave his memories alone and let him sort it out, even if it's risking a permanent crash.

* Variation in ''Recap/KamenRiderExAidKamenSentaiGorider''. [[Series/KamenRiderExAid Emu Hojo]] had to clear a game that was endlessly spawning monsters in the real world, but every time he died in the game, he had to start over with his memories erased. His only saving grace was a NoteToSelf coded in a GoroawaseNumber...[[CouldntFindAPen written in his blood as he died last time.]]

* ''Literature/HaruhiSuzumiya'': During the "Endless Eight" arc, everyone except Yuki has their memories of the GroundhogDayLoop erased at the end of said loop. This is a problem, as they are trying to figure out how to end it.

* In ''Manga/NanatsuNoTaizai'', [[spoiler:King]] erased Diane's memories of their first friendship so she wouldn't see the horror he did in his job. They meet again some years later, starting a chain of events that leads Diane to remember, but [[spoiler:Gowther]] erases her memories again [[MadScientist as part of an experiment]].

* ''LightNovel/HaruhiSuzumiya: Endless Eight'': Everyone except Yuki has their memories of the GroundhogDayLoop erased at the end of said loop. This is a problem, as they are trying to figure out how to end it.

* The second season of ''Series/TheGoodPlace'' opens during one of these. Every time the four main humans work out that [[spoiler: they're actually in the Bad Place being tortured]] Michael wipes their memories forcing them to start from scratch and work out the truth again. They have to go through ''802'' cycles of this before Michael finally stops wiping their memories.

* ''LightNovel/HaruhiSuzumiya: Endless Eight'': Everyone except Yuki has their memories of the GroundhogDayLoop erased at the end of said loop. This is a problem as they are trying to figure out how to end it.

* In ''Manga/TsubasaReservoirChronicle'', every time C!Sakura figures out her missing memories are about C!Syaoran (the ones she sacrificed for them to travel dimensions), she forgets again.

* The ''Anime/{{Pokemon}}'' fic "[[https://www.fanfiction.net/s/13653421/6/Ash-s-Adventure-Girls-Hunter-Edition Ash's Adventure: Girls' Hunter Edition]]" reveals that the Nurse Joy of Viridian City is basically stuck in one of these; every time she learns the scale of Team Rocket's influence in the city, she is taken to their base to be interrogated by a Psychic [=PokeGirl=], and then her memory is wiped of the events that inspired her suspicions so that she doesn't remember anything (Team Rocket allegedly consider this simpler than killing her and drawing attention to her disappearance).

[[folder:Film — Live-Action]]

* ''[[ComicBook/{{Sleeper}} Point Blank]]'': This is what becomes of Grifter's attempt to investigate Lynch's shooting, due in no small part to his drinking problem.

* Defied in ''Webcomic/{{Freefall}}'' -- when Florence gets kidnapped onto a top-secret military base, the commander uses direct orders to forbid her from talking about it, instead of a memory wipe, ''specifically'' because he knows that anyone with missing memories would try to find out what happened to them.

* ''Fanfic/InfinityTrainFanfic'' has this as TheReveal in Chapter 10: Tulip has been stuck on the train for over a century, but she doesn't remember because she keeps getting her mind wiped by the Conductor and sent back to the end of the train every time she fails to beat him. The TimeyWimeyBall nature of the train (which merges several {{alternate timelines}} together) additionally mess with her age and memories of getting on the train. The current loop has her as a 13-year-old, but others have had her as a preteen, older teen, and an adult.

A situation where an investigator is pursuing a single investigation while hampered by a faulty memory, as in ''Film/{{Memento}}'' or ''Ghajini'', is ''not'' an example of this trope, unless it includes the specific situation where the investigator completes the investigation and then starts over because they've forgotten that they completed it.

* Supernatural example in ''Film/{{Triangle}}''. [[spoiler: Jess keeps losing memory of the previous loop when she falls asleep on the yacht, and the first thing she says on waking up is "I don't remember."]].

* Implied to have happened several times with Leonard Shelby in ''Film/{{Memento}}''. Leonard is implied to have killed several people who he thought killed his wife, then destroyed the evidence of "success" after the killings, then was driven to find a killer all over again. [[spoiler: If Eddie is to be believed, they killed the person who broke into Leonard's house a long time ago and on top of that, its actually Leonard himself who accidentally killed her, though she's as much to blame. ]]

* Supernatural example in ''Film/Triangle''. [[spoiler: Jess keeps losing memory of the previous loop when she falls asleep on the yacht, and the first thing she says on waking up is "I don't remember."]].

Stories involving an Amnesia Loop are often told from the point of view of the investigating person, with "this isn't the first time this has happened" coming in as the big twist. Doing it that way also lets the writers establish the repetition without making the audience have to sit through it more than once.

* ''Series/BuffyTheVampireSlayer'' season 5: whenever a human learns that BigBad Glory is [[spoiler:hidden/trapped inside the body of Ben]] they forget very shortly afterwards; as a result the scooby gang learns this secret on multiple occasions.