History Main / SomedayThisWillComeInHandy

* Subverted in ''Film/{{Titanic 1997}}'': While being given a tour of the ship, Rose's entourage is shown the equipment in the Titanic's gymnasium, which includes a rowing machine. When offered to give it a try, Rose's mother remarks, "Don't be absurd. I can't imagine a skill I should likely need less!"

* Back in volume 4 of ''LightNovel/HighSchoolDxD'', Sirzechs asks Issei as to what happens if the latter uses [[StatusBuff Gift]] on Rias' breasts, then tells him not to worry about it. Seven volumes later, [[spoiler:the spirits of the past Boosted Gear users bring it up again and sure enough, Issei uses said skill(with permission from Rias, who readily accepts), and the end result? Rias becomes a ''battery'' for Issei at the cost of her breasts ''shrinking'']].

* In ''VideoGame/FatalFrame'' 4, Ruka's mother taught her a specific song on the piano and it is one of the few memories she has from her childhood. It turns out to be vital, because [[spoiler: it is the sacred Tsukimori Song, the only thing capable of defeating Sakuya]].

* ''VideoGame/{{Portal 2}}'': (paraphrased) "Moonrocks crushed into powder and then mixed with water"..."makes a great conductor for portals" becomes extremely useful during the final boss battle, not only at the beginning but [[spoiler:at the end your character shoots a portal into the moon, thereby sucking the BBEG into space]].

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* ''WesternAnimation/TeenTitans''. Beast Boy's bottomless well of TV trivia knowledge ultimately allows the Titans to defeat Control Freak, who was only dangerous because he also possessed a bottomless well of TV trivia knowledge.

* ''VideoGame/{{Portal 2}}'': (paraphrased) "Moonrocks crushed into powder and then mixed with water"..."makes a great conductor for portals" becomes extremely useful during the final boss battle, not only at the beginning but [[spoiler:at the end your character shoots a portal into the moon, thereby sucking the BBEG into space]].

* In ''VideoGame/FatalFrame'' 4, Ruka's mother taught her a specific song on the piano and it is one of the few memories she has from her childhood. It turns out to be vital, because [[spoiler: it is the sacred Tsukimori Song, the only thing capable of defeating Sakuya]].
* In ''VisualNovel/{{Policenauts}}'', local explosive expert Redwood challenges the main character Jonathan to guess which of the two wires - red or blue - must be cut to defuse the bomb he built. Jonathan guesses red "for Redwood", only for Redwood to chastise him for believing that a bomb-maker will always stick to their usual methods. Half game later, Jonathan is put in a similar situation, and he's specifically reminded of Redwood's words. [[spoiler:The player, however, must remember that [[ReversePsychology Redwood repeatedly lies to Jonathan]]. Since he built the bomb, the correct answer really is "red for Redwood"]].

-->-- ''[[Literature/{{Belgariad}} The Malloreon]]'', '''Creator/DavidEddings'''

* In ''WesternAnimation/TheSimpsons'''s "Treehouse of Horror V", Homer recalls the advice his father gave at his wedding: namely, explaining TheButterflyEffect in the context of time travel and warning Homer not to touch anything.

* ''Series/{{QI}}''.

* On ''Series/{{Cheers}}'', [[TheClavin Cliff]] somehow [[ShowWithinAShow ends up a contestant]] on ''Series/{{Jeopardy}}''. The clue categories align perfectly with his idiosyncratic "knowledge" (mothers, the Post Office, etc). He dominates the first rounds, amassing a pile of winnings, but of course ends up stupidly [[ResetButton blowing it all]] in Final Jeopardy.

* The Hermit, one of the TAROT villains from the ''Roleplay/GlobalGuardiansPBEMUniverse'' retains a perfect memory of everything he ever experienced from the time of his childbirth, and is a voracious reader. He's also one of the world's smartest people, allowing him to put his EncyclopedicKnowledge of ''everything'' [[CrazyPrepared to use against his opponents]]. He's a villain the heroes hate going up against, simply because he's so annoyingly effective.

ChekhovsHobby and ChekhovsClassroom leads to this. Compare FigureItOutYourself, YouWillKnowWhatToDo.

* Ian from ''Manga/FairyCube'' has read every book that has any information on fairies since childhood. When Kaito transports him to the Otherworld and Ian has to proceed to get back out, he uses his knowledge to fight, using a pair of iron scissors that are an effective weapon against fairies and gets Ainsel across a sweetwater river, so that the Nuckelavee chasing them can't follow them.

* A short ''Franchise/{{Batman}}: Black and White'' story by Creator/WarrenEllis and Creator/JimLee features Batman hunting down a murderous senator and fighting his way through his goons. Each skill that Batman uses is followed immediately by a one or two panel flashback showing how he learned it. These include [[CrazyPrepared building a remote control, knowing the smell of every aftershave ever, knowing the exact hole size and shape different caliber bullets make in different body parts, kicking a tree in half and identifying how recently someone had a manicure from the nail impressions left in skin.]]

** A security guard conveys suitably detailed explanation about the whereabouts of the big-time music producer Frank Sharp. Wayne hangs a lampshade on it at the time by commenting "For a security guard, he had an awful lot of information, don't you think?" Wayne lampshades this again later, when Sharp's whereabouts suddenly become important: "Aren't you glad we were there to hear that information? Seemed extraneous at the time."
** The sequel does something similar as well. When Wayne and Garth arrive outside of a studio, a number of men are doing things such as moving a window back and forth across the street, stacking fruit, and so on. When asked why, the workers reply that it's just their job. Later on Wayne crashes through them all in his car in a stereotypical "action sequence", causing the workers to state in satisfied fashion that their job is done. Of course, the "handiness" of this is almost entirely under the RuleOfCool.

* It probably qualifies more as a ContinuityNod than anything else, but a cut scene in the 1979 sci-fi classic ''Film/{{Alien}}'' shows Warrant Officer Ellen Ripley reading a bioscanner for crewmember Kane, and failing to understand that he's had an organism planted inside of him. This scene pays off in the third film, when Ripley gets prison staff member Andrews to scan her using her crashed escape pod's bioscanner, and she knows where and how to scan for anomalies.

* Creator/LarryNiven [[LampshadeHanging lampshades this]] in his ''Literature/KnownSpace'' series. Two of his earlier ''Known Space'' stories, "Eye of the Octopus" and "How the Heroes Die" detail the early manned exploration of Mars, and include the characters collecting seemingly trivial data about the planet that isn't useful at the time. In the novel ''Literature/{{Protector}}'', set a hundred years later, the trivia about Mars is finally put to use. When asked how the Terrans knew such useless knowledge would one day be useful, Lucas Garner says, "No knowledge is really useless... you'll always find some use for it sooner or later."

* This is Invoked by Music/TomLehrer on the live album ''Music/AnEveningWastedWithTomLehrer'', when introducing "The Elements", a song which lists the chemical elements (at least, those known at the time) "set to a possibly recognizable tune".
-->'''Tom Lehrer:''' This may prove useful to some of you some day, perhaps, in a somewhat bizarre set of circumstances...

* Done in ''VideoGame/BanjoKazooie''. Throughout the castle, you'll come across Gruntilda's (good) sister Brentilda, who will happily tell you all of Gruntilda's embarrassing secrets. Later on, when Grunty challenges you to a quiz style board game, these secrets become your only means to win. Note that it's possible to avoid answering the "Gruntilda Questions" for the most part if you make a slight detour to get a Joker (which lets you skip a Question). In fact it's possible to finish the Board without having to answer ''any'' Gruntile Question. Also, the answers to each question is different, and change with each play through of the game. So getting Brentilda to give you the facts becomes necessary each time you play.

* In ''VisualNovel/{{Policenauts}}'', local explosive expert Redwood challenges the main character Jonathan to guess which of the two wires - red or blue - must be cut to defuse the bomb he built. Jonathan guesses red "for Redwood", only for Redwood to chastise him for believing that a bomb maker will always stick to their usual methods. Half game later, Jonathan is put in a similar situation, and he's specifically reminded of Redwood's words. [[spoiler:The player, however, must remember that [[ReversePsychology Redwood repeatedly lies to Jonathan]]. Since he built the bomb, the correct answer really is "red for Redwood"]].

** Phase learning about "giants" (size Warpers who use a warp field to appear to grow to giant size) in class, and then using that to defeat one in Boston. He also uses the same tactic to defeat the Vindicators in the beginning of ''Ayla and the Birthday Brawl'' -- he takes over Sizemax's field and uses her like a meteor hammer.
** Phase is made of this trope, when he's not being CrazyPrepared or a ShelteredAristocrat. There's the lecture he gave on fighting other mutants in "Ayla and the Birthday Brawl". There's the training manual he read in "Ayla and the Great Shoulder Angel Conspiracy". There's the financial expertise he learned about as a child in a super-rich family. There's the knowledge about religious icons he wields in "Ayla and the Grinch". And so on...

** The genie he meets while travelling though the desert, who gives him his costume and his signature smoke-intro.

* Pub Quizzes often have sections which are basically set up to encourage this.

* ''[[http://en.wikipedia.org/wiki/Academic_Bowl Quizbowl]]''. Being a repository of completely random knowledge is an immense asset. Subverted by the [[http://www.qbwiki.com/wiki/Canon Canon]], thanks to which, experienced players can predict fairly accurately what topics will come up and study accordingly. Probably most of the points good players accumulate are the result of targeted accumulation.

* ''Series/TheHoneymooners'', episode "The $99,000 Answer". Music-guru Ralph learns he is to be a contestant on a music trivia game show and Norton helps him practice for the show by playing snippets of various songs on the piano. To Ralph's ever-increasing annoyance, Norton always warms up by playing the first two lines of "Old Folks at Home" ("Way down upon the Suwanee River, far far away"). When Ralph confidently appears on the game show, the first musical clue he hears is the same two lines that Norton always warmed up with. Ralph is dumbstruck, can't come up with the answer, and is eliminated from the game on the very first question. For the record, [[CrowningMomentOfFunny he guessed that Norton composed it]].

* In ''Literature/{{Island}}'', Ian is a little kid who spent all his time watching the Discovery Channel and other informative TV channels. It ends up saving the group's life more than once when the group of preteens, ages 11 to 14, get marooned on an uncharted island by themselves [[spoiler:well, not really by themselves. There's also a terrorist group on there too]].