History Main / RetroactiveIdiotBall

** When Rafiki appears to tell Simba's friends that he's gone back to the Pride Lands, a confused Timon asks "Who's the monkey?". But in ''WesternAnimation/TheLionKingOneAndAHalf'', a POVSequel, it's revealed that Timon actually met Rafiki much earlier in the narrative (as in ''before the original's narrative even started'') and that in fact, Rafiki was the one who taught him the "Hakuna Matata" motto and that Timon's whole journey that led to him ending up in the place he's introduced in the original movie was based on him being LiteralMinded and misinterpreting Rafiki's advice, meaning that he should have known who the monkey was.

* In ''Film/SawIV'', TheReveal is that Mark Hoffman, one of the detectives involved in the Jigsaw case, [[DetectiveMole is actually working for Jigsaw,]] and the [[Film/SawV next film]] explains why; the man who killed Hoffman's sister got OffOnATechnicality, so Hoffman killed the man by copycatting one Jigsaw's killings, then got recruited by the real Jigsaw, John Kramer, who was easily able to track him down because, without the serial-killer connection, Hoffman is the obvious suspect in the killing. But then why was Hoffman allowed anywhere near the Jigsaw case if there was such a massive conflict of interest that was easily found out? Hell, why wasn't Hoffman a prime suspect for being Jigsaw or one of his accomplices from the start? The [[Film/Saw3D seventh film]] makes this even worse by revealing Hoffman had a history of PoliceBrutality, which would lend itself well to Jigsaw's KnightTemplar MO.

** ''Anime/PokemonTheOriginalSeries'': Thanks to EarlyInstallmentWeirdness, nearly every character in the first season, regardless of their status, would act as if there were only 150 Pokémon known to exist, as was the case in [[VideoGame/PokemonRedAndBlue in the first generation of Pokémon games]].[[note]] While there were in actuality 151 Pokémon introduced in Generation I, within the games and anime [[OlympusMons Mewtwo]] is a top-secret project that few know the existence of.[[/note]] Bill's hypothesis that there could be more than 150 Pokémon is treated as an absurd theory will little evidence, and [[EarlyBirdCameo Togepi]] gets treated as a newly discovered species. However as time passed the franchise would vastly expand, to the point there are now over 1,000 Pokémon spread across multiple regions, with their existence being common knowledge. [[BackportedDevelopment Several flashbacks in later shows would ignore the idea that any character thought there was only ever 150 Pokémon]] and give them substantial interactions with species introduced in later generations. For example, despite James once being flummoxed by the existence of Togepi, ''Anime/PokemonTheSeriesDiamondAndPearl'' would reveal he's owned a Carnavine (a species not introduced until [[VideoGame/PokemonDiamondAndPearl Generation IV]]) since childhood.

** During the Majin Buu Saga, Vegeta has let himself be corrupted by Babidi's "Majin" spell in order to force a fight against Goku. In response, Goku fights Vegeta in a prolonged battle using his full power, the same Super Saiyan form (SS 2) that Gohan used during his fight with Cell. Not long after though, Majin Buu becomes released due to the energy generated by said fight, Gohan is thought to have been killed by Buu, Vegeta is dead after a failed sacrifice to kill Buu, and Goku needs to stall Majin Buu, so he confronts Buu and reveals Super Saiyan 3. Not only does this make him hiding this look silly, it also makes him fighting Vegeta look even dumber; Super Saiyan 3 not only would have been strong enough to defeat Vegeta, but he likely could have defeated Buu with said form if he had done so. The only justification Goku has is that it burns through his ki at a frightening rate (it's only viable when he's dead in Other World) and he might need it later, but it makes him doing so seem like an idiot, since he could have used it to defeat Vegeta, then go and try to and help stop Buu. Vegeta later calls him out on hiding it when he is temporarily revived.

** Initially, Itachi said he killed the Uchiha clan to test how strong he could become, and spared Sasuke because he was curious to see if Sasuke would follow in his footsteps, setting up Sasuke's desire for revenge and power. Years later after his death following an intense fight with Sasuke, it's revealed Itachi actually did all that because he learned his clan was going to stage a coup to overthrow the village, and being loyal to the village, killed all but Sasuke, who was spared as part of the arrangement, and lied to convince Sasuke to one day kill him to be seen as a hero by the village. The problem is that Itachi went out of his way to push Sasuke to want more power, which lead Sasuke to defect from the village and join Orochimaru, who Itachi knows wants an Uchiha's body for BodySurf reasons. If his goal was to convince Sasuke to stay in the village and become a hero, it backfired because Sasuke learning the truth made him hate the village enough to want to destroy it in response. Even if he assumed Sasuke would never learn the truth, he directly encouraged and caused Sasuke to become a fugitive even before his death, making the supposedly genius Itachi who was trying to protect his brother and the village look dumb for not doing either right. It speaks volumes when Itachi himself admits to this mistake and has to entrust Sasuke to Naruto.
** Back when Naruto first interacted with the Nine-Tailed Fox within him, the latter gave the him his Chakra despite his clear resentment at being imprisoned because it was originally stated that if Naruto dies, then the Fox dies as well. However late in Part II, it is later revealed that the Tailed Beasts will revive some time after being killed as shown what happened with Rin & the Three-Tails and the Fox himself knows it. By the time the revelation is known, Kurama is already on the verge of genuinely caring about his host but given that he initially wants to be free and away from humans after being trapped for so long, it begs the question of why he even protect Naruto at all when simply letting him die would have allowed him to accomplish said goals far sooner than expected.