History Main / AmnesiaLoop

* [[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.

* ''ThePenguinsOfMadagascar'' has an episode with Private finding a bottle of "[[http://www.youtube.com/watch?v=KTM3k0tqqoM Amnesia Spray]]":

* ''CaseyAndAndy'': The title characters watch a movie, then decide that they want to be able to enjoy the twists again, so they erase their memories of watching it and watch it again. It later turns out that they had done this around 60 times for that particular movie.

A situation where an investigator is pursuing a single investigation while hampered by a faulty memory, as in ''{{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.

* Implied to have happened several times with Leonard Shelby in ''{{Memento}}''. Leonard is implied to have killed several people who he thought killed his wife, than destroyed the evidence of "success" after the killings, then was driven to find a killer all over again.

* Kronk on ''TheEmperorsNewSchool'' does this in order to keep Mudka's Meat Mugs recipe a secret, even from himself despite being the chef, by dropping a grand piano on himself. Hilarious in that the only ingredients in the recipe is [[[spoiler:salt and pepper]].

* On ''AmericanDad'', every year Francine brings up the idea of having her parents move closer to them. Every year Stan takes her to a hypnotherapist to wipe the idea from her mind.

* In the old pre-reboot ''[[MageTheAscension Mage: The Ascension]]'', this was created by a massive spell cast around the truth of the origin of the Virtual Adepts. It was finally discovered when someone assigned to go over some stolen Technocratic information sat down to read for a few minutes, and discovered he'd been reading for several hours.

* In an episode of ''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 SufficientlyAdvancedAliens 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 into yet another investigation loop, since, if they come back a third time, they almost surely ''will'' get killed next time by the increasingly annoyed aliens.

* In one episode of ''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 let him sort it out, even if it's risking a permanent crash.

* In an episode of ''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 SufficientlyAdvancedAliens who'd wiped their memories to avoid having to kill them 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 into yet another investigation loop, since, if they come back a third time, they almost surely ''will'' get killed next time by the increasingly annoyed aliens.

* In an episode of ''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 [[spoiler:they investigated the anomaly before and uncovered a group of xenophobic SufficientlyAdvancedAliens who'd wiped their memories to avoid having to kill them to keep their existence a secret]], which created the missing time period. Once the truth's revealed, the crew redoubles its efforts to [[spoiler:cover up the events all over again]] so they won't go into yet another investigation loop, [[spoiler:since, if they do it again, they almost surely ''will'' get killed next time by the increasingly annoyed aliens]].

* In one episode of ''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.

* In the ''DoctorWho'' episode "The Beast Below", there's a secret at the heart of the kingdom, and Liz X is determined to uncover the truth. Part of the truth she uncovers is that she's uncovered the truth many times before, but always agreed to undergo LaserGuidedAmnesia to allow it to remain secret.

* Also happens in ''StarTrekTheNextGeneration'', in the episode "Clues".

A character notices something unusual, investigates it, discovers a big secret, and is given LaserGuidedAmnesia to keep the secret safe. All is well... until they notice the unusual thing again, and, since they have no memory of last time, starts the same investigation over again.

* Beautie in the ''AstroCity'' story "Her Dark Plastic Roots" is a life-size "Beautie Doll" (an {{Expy}} for {{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.

* Endless Eight in HaruhiSuzumiya.

[[folder:Manga]]

* ''RubyQuest''. It's hinted early that it's not the first time YouWakeUpInARoom, but the full extent is only revealed near the end: It's been going on for [[spoiler:a full year]].