->'''Bart:''' Dad, you killed the zombie Flanders!\\
'''Homer:''' He was a zombie?
-->-- ''WesternAnimation/TheSimpsons'', "Dial Z For Zombie"

StockPhrase uttered in which our hero attacks a seemingly InnocentBystander but discovers that the bystander was not what he appeared.

Goes as follows:

->'''Sidekick:''' How did you know he/she was an evil X?
->'''Hero:''' I didn't...

Borders on IndyPloy for charging in with no other plan and MoralDissonance when you realized that our hero had no problem killing someone and just happened to land on the accepted side of WhatMeasureIsANonHuman. Alternatively, sometimes the hero might have known the truth all along and just be yanking the chain of the person asking the question.

This may also be used in a SpotTheImposter scene, when the hero's choice turns out to be correct.

However, it can also be used to show the hero's courage, as in: "How did you know that bomb wasn't real?" "I didn't." (It's also used as a punchline, where the hero [[AndYouThoughtItWasAGame retroactively freaks out when they realize how much danger they were in.]])

Not to be confused with YouJustToldMe, although the same phrase can be used for that purpose too. Also not to be confused with AccidentalTruth. See also IHaveNoIdeaWhatImDoing.


[[folder:{{Anime}} and {{Manga}}]]
* In an OVA from ''Anime/FullmetalAlchemist'', Ed and Al get caught up with the Homunculi after Envy shapeshifts to pretend to be a captured Winry. They escape, chaos ensues, and Edward ends up taking out Envy who's disguised as Roy Mustang.
--> '''Al''': Oh wow, Ed, how did you know that wasn't the Colonel?
--> '''Ed''': ... it wasn't?
* This speech follows pretty much every victory of Anime/IrresponsibleCaptainTylor. It comes to the point where his second in command begins to anticipate the 'I didn't' reply. He becomes smart enough that he decides to imitate Tylor's style when mounting his rescue operation. And yes, it also works when he does it.
* An extreme example occurred in ''Manga/{{Saiyuki}}'' when the entire group sans Gojyo decided that the next time they saw Gojyo, they'd beat the crap out of him for leaving their group and throwing off the dynamic. They meet an evil doppelganger Gojyo and naturally start to beat the crap out of it. When they discover it isn't Gojyo they decided to pretend it is and proceed to tear it to shreds as a catharsis.
** Especially funny because the guy disguised as Gojyo fully expected them to pull the "[[ShapeshifterGuiltTrip How can I bring myself to fight my friend?]]" act... [[GoodIsNotNice Ehehe.]]
* On ''Manga/YuYuHakusho'' Yusuke is faced with a SpotTheImposter predicament and is told he has to punch the culprit as hard as he can to expose him. He correctly chooses Kuwabara but only did so because he knows Kuwabara is used to being hit by him while ruling out the others. He did mention before doing so that he hoped he was right.
* In ''Manga/JoJosBizarreAdventureDiamondIsUnbreakable'', Okyuasu (who is not very smart) is facing two people who both claim the other is an impostor who snuck in to kill Joseph. When the impostor's Stand moves in for the kill, Okuyasu punches one of the men, who turns out to be the villain. The defeated bad guy asks how Okuyasu knew, and he reveals he was planning on punching ''both'' of them - he just happened to get the right target first by luck.
* A ''Anime/SailorMoon [=SuperS=]'' special starring Haruka and Michiru has Sailor Neptune fighting a living puppet and his master at a hotel, and the puppet holding an ill Haruka hostage. Neptune is about to save her by destroying the puppets source of power, but warns her that doing so will cause the shadows of every person on earth to kill their hosts. But Neptune destroys the power source anyway and sarcastically asks if "the shadows have begun to run rampant yet". The puppet asks how she knew he was lying, but it turns out ''she didn't''. The bad guys [[WhatTheHellHero call her out on risking the lives of other people]], but Neptune simply responds, "A world without Haruka isn't worth saving".
* Played very cleverly during the second arc of ''Anime/YuGiOh5Ds'': All the little kids in the orphanage are depressed about how Martha and others have been taken by the Earthbound Gods. Yusei sounds like he's very GenreSavvy about NoOntologicalInertia when he assures them that when they defeat the villains, everyone will return and be all right. After the kids leave, his adult and teenaged allies ask him how he knows that. He sheepishly admits he doesn't -- he just said it to cheer them up. [[WhatTheHellHero To say they're not too happy is an understatement.]] [[spoiler:Fortunately for everyone, it does turn out to be true.]]
* On the way to the Hunter Exam in ''Manga/HunterXHunter'', Kurapika hits Leorio in the face with his nunchucks. "Leorio" then transforms into a monstrous creature and asks how Kurapika knew he was an imposter. Kurapika responds that he didn't know, he just wanted to hit Leorio in the face. (Because Kurapika assumed that Leorio had abandoned the wounded man he had promised to take care of.)

[[folder: Audio Drama]]
* In the ''AudioPlay/BigFinishDoctorWho'' audio play ''The Chaos Pool'', the Doctor throws himself into the Pool to disperse the Key to Time. His companions are convinced he's sacrificed himself until he calls out that he'd like some help getting back up. When they ask him how he knew he'd survive, he evades the question and they realize he didn't.

[[folder:Comic Books]]
* ''Comicbook/TheAvengers'' #1½: TheHulk is attacking a Dr. Doom robot and is asked (after he smashes it) how he knew it's [[ActuallyADoombot a robot]]. "Robot?"
* ''ComicBook/BirdsOfPrey'' #97: ComicBook/{{Cheetah}} tackles ComicBook/BlackCanary and threatens to rip her throat out. ComicBook/{{Huntress}} shoots Cheetah in the shoulder, face, and throat.
-->'''Black Canary:''' Hey, how'd you know about Cheetah's healing factor?\\
'''Huntress:''' Healing what now?
* In Marvel's ''[[ComicBook/GIJoeARealAmericanHeroMarvel G.I. Joe]]'' comic, Sgt. Slaughter is confronted by two Gung-Hos. He punches one in the face who turns out to be the shapeshifter Zartan. When asked how he knew which one to punch, Slaughter replies, "Lucky guess."
** The IDW reboot pulls it off without the double. Duke cold-clocks Snake-Eyes as soon as he appears during a mission off sheer suspicion, and it turns out to be Zartan. Duke says he didn't ''need'' to actually know: There was no way he could've hit the ''real'' Snake-Eyes.
* A variant occurred in the comic book ''ComicBook/SpyBoy''.
* An issue of ''ComicBook/FantasticFour'' had a future version of Namor and Black Panther coming to the present for some reason or another. It's revealed that Reed's devotion to his work would eventually drive his family away from him, culminating in Susan running off with Namor (as she's been on the verge of doing before). Reed takes this news calmly, then shoots Namor in the head. In this case, he suspected, but did not know for certain, that this was a plot orchestrated by Doom, and that the future Namor and Black Panther were robot impostors.
** Reed based his decision on 'well I can't believe Doom solved that external power supply problem for that type of force field so Namor and Black Panther must be androids holding the power supplies'. He was so certain Doom couldn't have solved a problem he couldn't even from decades into the future that he was willing to risk killing what was possibly the real Namor to prove himself right. Presumably, he shot the Namor android because he'd care a lot less about Namor dying if he turned out to be wrong.
* ''ComicBook/TheMaxx'': the BigBad takes what is assumed to be a girl hostage. Maxx smashes the girl's face into a car, leaving the villain to wander off in a fit of anger. It was a CPR dummy, but Maxx very poorly tries to cover up his surprise it wasn't a real person.
* ''ComicBook/{{Runaways}}''
** An example played seriously occurred in the first volume: after a vampire ([[spoiler:Topher]]) had taken out nearly the whole team, Karolina offered to let him bite her in exchange for letting Molly live, claiming she wanted to die. He bit her--and spontaneously combusted, since she's a solar-powered alien. When Alex asked her how she knew that would happen, she admitted that she had actually been trying to commit suicide by proxy.
** Volume 3 #10: faced with a mutant cobra monster that's constantly respawning via eggs, Chase told Victor (a cyborg) to swallow the mutant cobra eggs in order to destroy the mother. Chase admits that he didn't know that it would work, but figured in the worst case scenario they could rebuild Victor.
* Issue 1 of the ''Dallas'' arc of ''ComicBook/TheUmbrellaAcademy'' features the Lincoln memorial statue come to life and terrorize the District of Columbia. To stop it Rumor says "Mr. President. I heard a rumor you were assassinated." This conjures up a statue of John Wilkes Booth who shoots the rampaging Lincoln. Hargreeves arrives on the scene and asks how she knew that would work. She replied, "I didn't."
* From ''ComicBook/FallenAngel'': This exchange after Lee drops Shadow Boxer off a roof and he lands in a hay truck.
-->'''Slate''': Pretty impressive, by the way. Timing Boxer's falling into that truck so he wouldn't be hurt.
-->'''Lee''': ''{{beat|Panel}}''. What truck?
* ''{{Wolverine}}'' Vol 3 #62, Wolverine and Mystique are tied up in front a Mexican firing squad. They escape.
--> '''Mystique:''' ''How'd you know I'd be able to untie myself before the shooting started?''
--> '''Wolverine:''' ''I didn't.''
* In ''[[ComicBook/NewAvengers The New Avengers]]'', Dum-Dum Dugan shoots Victor Creed in the head:
-->'''Victor:''' So... They told you about my [[HealingFactor healin' factor]].
-->'''Dum-Dum:''' He heals?
* In issue #1 of the original ''ComicBook/NewWarriors'', Night Thrasher drops Richard Rider off a rooftop in order to re-activate his Nova powers (which Richard thought he'd lost after returning to Earth... long story). You can guess what Nova's next question and Night Thrasher's response are.
* In ''ComicBook/AvengersAcademy'' #25, Hazmat blasts X-23 with a toxic blast after X-23 stabs Mettle:
-->'''Giant-Man:''' Careful! Her healing factor isn't as strong as Wolverine's!
-->'''Mettle:''' You knew she'd survive that, right?
-->'''Hazmat:''' Yeah. Woulda done it anyway.
* In the ''Series/BuffyTheVampireSlayer'' tie-in comic "Ring of Fire", Kendra attacks a man who turns out to be a demon. Xander asks how she knew. She didn't.
* In one issue of ''ComicBook/BatmanAdventures'', The Riddler is up to his old tricks, but another group of devious criminals is operating. So, Batman is forced to choose which rogue to chase after, and decides to go for the other party than bother with Riddler's obligatory riddle. By ''sheer coincidence'', both sets of Rogues hold their heists in the same building, allowing Batman to catch both. When Riddler asks how Batman solved his riddle, Batman just tells him, "I didn't" and Riddler is so happy to think he stumped Batman that he goes to jail singing a jaunty tune.

[[folder:Fan Works]]
* A variant from the ''WesternAnimation/MiraculousLadybug'' fic ''[[http://archiveofourown.org/works/7886854 Adrien and the Terrible, Horrible No Good Very Bad Day]]'', after Ladybug gives Adrien a long and comforting hug while apologizing for avoiding him after his identity was exposed.
-->'''Adrien''': You really are miraculous, LB. How'd you know that was exactly what I needed?
-->'''Ladybug''': I didn't know. I just knew ''I'' needed that.

* ''Film/MenInBlackII'': [[LaserGuidedAmnesia Amnesiac]] Agent K shoots alien pawn-shop clerk Jeebs in the head. [[RunningGag Again.]]
-->'''J:''' "You're back." \\
'''K:''' "No."\\
'''J:''' "How'd you know his head grows back?"\\
'''K:''' "It grows back?"
* ''Film/TheNakedGun 2 1/2'': Frank Drebin is being "honored for his 1000th drug-dealer killed." He responds: "Thank you. But, in all honesty, the last two I backed over with my car. Luckily, they turned out to be drug-dealers."
* ''Film/GetSmart'': Max is asked [[spoiler:where the bomb is at the concert. He says that it is under the piano. Naturally, that's where it was.]] The chief asks how Max knew. The answer: Lucky guess.
* ''Film/{{Unforgiven}}'' actively subverts a scene from ''Film/TheOutlawJoseyWales'' where Wales survives an assault from a dangerous posse, then explains how he carefully chose which member he had to shoot first based on a SherlockScan of which one was the most dangerous. In ''Unforgiven,'' after Munny survives a similar encounter, he just shrugs and says he got lucky when asked.
* ''Film/{{Papillon}}'' (1973) takes shelter in a leper colony after his escape, and is invited to share a cigar by their leader. Despite his fear of catching the disease, Papillon does so. There's a moment of silence from the leader (who clearly expected him to refuse) before he asks how Papillon knew he had dry leprosy, which isn't contagious. When Papillon replies that he didn't know, it breaks the ice between the two men.
* In the movie version (but not book) of ''Film/TheHuntForRedOctober'', Jack Ryan and Captain Mancuso invoke this trope, in regards to which way Captain Ramius would turn for the next "Crazy Ivan" maneuver.
* ''Film/MacGruber'':
--> '''Piper''': "How did you know I was wearing a bulletproof vest?!"
--> '''[=MacGruber=]''': "You were wearing a bulletproof vest? Awesome!"
** An interesting spin on this trope is that it was the final straw for Piper and he temporarily quits the team.
* In ''Literature/TheDayOfTheJackal'', Commissioner [=LeBel=] believes that a member of the French Cabinet is leaking confidential information to The Jackal. [=LeBel=] plays a tape of a telephone conversation to the entire Cabinet, showing that one of their members had been betraying them. Another Cabinet minister asks him how he knew which one of their phones to tap. "I didn't, so I tapped all of them." Only the Prime Minister is unsurprised, since he gave [=LeBel=] unlimited authority in the first place.
* It happens in the loose 1997 adaptation ''Film/TheJackal'' too, where the FBI Deputy Director has been led to believe that someone in the FBI has been leaking information to the Jackal. He does the same thing to get a tape of a phone conversation recorded on a tapped line.
* The question is reversed in ''Film/{{Splice}}'' when [[spoiler:Elsa asks Clive if he knew that Dren had water lungs the whole time. He lies and says yes when he was actually trying to drown her.]]
* ''Film/KeepingMum'', after Gloria and her daughter Holly learn in short order that the new housekeeper is a paroled murderer who killed again, and is also Gloria's long-lost mother.
-->'''Gloria''': Aren't we forgetting the small matter of dead bodies?\\
'''Rosemary''': How did you know about the other bodies?\\
'''Gloria''': What other bodies?\\
'''Rosemary''': *relieved* Oh, you didn't know about the other bodies.
* ''Film/DiamondsAreForever''. A Mafia {{mook}} throws Plenty O'Toole, one of the Bond girls, off of a high floor, and she lands unharmed in a swimming pool below. When Bond compliments him on his aim, the mook replies, "I didn't know there was a pool down there."
* In ''Film/PiratesOfTheCaribbeanOnStrangerTides''. Blackbeard forces Jack to play a variant of RussianRoulette with four unloaded pistols and two loaded ones, and Angelica (his daughter, Jack's love interest) as the target. When Jack takes the option to jump instead, Angelica asks her father if he knew which guns were loaded. He (unconvincingly) says he did, but considering his later actions there's no reason to believe he would care about putting his daughter in danger.
* Used on the Podcast/RiffTrax for the opening of ''Film/TheDarkKnight''.
--> '''Mike:''' (imitating the bank manager with a rifle) ''What ?! He was robbing my bank! I thought he was just a clown!''
* ''Film/TheConspirator'': Aiken mistakingly asks a question at trial without knowing the answer. It was dumb luck that it worked in his favor, and he confesses this to his friends.
* ''Film/TheWolverine'': After Logan finishes interrogating Noburo Mori, Minister of Justice [[spoiler:and Mariko's [[BastardBoyfriend Bastard Fiancé]]]], he throws him over the balcony of his penthouse, to have him land in the pool below.
-->'''Yukio:''' How did you know there was a pool down there?\\
'''Logan:''' I didn't.
* ''Film/WorldWarZ'': [[spoiler:Jerry uses this line after one of the WHO Doctors asks him how he knew that injecting himself with a virus to camouflage him from the zombies.]]
* ''Film/TerminatorGenisys''. Sarah Connor encounters a T-1000 disguised as Kyle Reese at about the same time the actual one comes in. After a short standoff, she shoots one in the foot and it's the T-1000. Kyle is not amused when Sarah admits that she wasn't totally sure and so went for a non-fatal wound.
* In ''Film/TheManFromUNCLE2015'' when Napoleon asked how Victoria knew which liquor he'd drink (because he discovered she drugged it), Victoria blithely said she didn't, so she drugged them all.
* ''Film/{{Alien 3}}'': A bit before the climax, Dillon off-handedly asks about Ripley having slept with Dr. Clemens in a way that implies he already knew. When she replies that he's obviously been a peeping tom, he says that he wasn't, but her response did confirm his suspicions.
* Inverted in ''Film/VanHelsing''. After Anna stops Van Helsing from shooting her brother-turned-werewolf, he shouts, "He's not your brother anymore!" She asks if he knew before or after she stopped him -- thinking he would not have shot if he didn't realize it -- and he answers that he knew before she stopped him.

* In ''[[Literature/ShadowOfTheTemplar High Fidelity]]'', after spying on Jeremy[[spoiler:'s deal with Bran]], Simon asks Jeremy how Jeremy had been sure that [[spoiler:Bran]] had been bluffing about [[spoiler:demanding a blowjob ''at gunpoint'']].
-->'''Simon:''' How'd you know he wasn't serious about it?
-->'''Jeremy:''' About what?
-->'''Simon:''' About [[spoiler:blowing him]]. How'd you know he didn't mean it?
--->[''after a short pause'']
-->'''Simon:''' You didn't know, did you.
-->'''Jeremy:''' [...] I suppose you could say that I didn't know for certain--but I hoped.
* Happens in ''Discworld/TheScienceOfDiscworld'' when the Dean sticks his hand into the nascent Roundworld project:
-->"That was a really very foolish thing you just did," said Ridcully. "How did you know that it wasn't dangerous?"
-->"I didn't," said the Dean cheerfully. "It feels... cool. And rather chilly. Prickly, in a funny sort of way."
* In ''Literature/TheDayOfTheJackal'', when asked how Lebel knew which minister was being spied on by a mole, he answered he didn't know...so he tapped ''all the ministers' phones.''
* ''Literature/JoePickett'': In ''Stone Cold'', a bomb goes off that takes out two local thugs who are trying to kill Joe. However, this was not the reason Joe had planted the bomb, leading to this exchange with Nate:
-->"How did you know there was a bomb inside the wall?"\\
"I put it there. Critchfield thought it was still under my truck."\\
"How'd you know he'd park there?"\\
"I didn't."

[[folder:Live Action TV]]
* ''Series/NedsDeclassifiedSchoolSurvivalGuide'' has Cookie as the "new kid" posing as a British person to seem more interesting to his new class. Turns out the class already has a British kid, who calls him out on it. Cue Cookie stammering and then trying to save face by sputtering miscellaneous stereotypical and nonsensical Britishisms. Then it turns out he was [[FakeBrit faking]] as well; he's from Ohio, not Britain. Cookie asks "Then how did you know I wasn't British?" The response? "I didn't. I just took a stab and you ''caved''."
* The MadeForTVMovie ''ComicBook/NickFury, Agent of SHIELD'' (with Creator/DavidHasselhoff as Nick Fury). Nick shoots Director Princer, who turns out to be an Evil Life Model Decoy, but Nick didn't know this. He just hated Princer.
* A BadBoss example is in the ''Series/BuffyTheVampireSlayer'' episode "Band Candy". Mr. Trick accuses a worker of sampling the cursed product and {{Neck Snap}}s him. Ethan Rayne asks Trick how he knew the worker was stealing. Trick replies that he didn't "[[MakeAnExampleOfThem And now no-one else will either]]."
* In a season 5 episode of ''Series/{{Angel}}'', Wesley shoots (repeatedly) someone who turns out to be a robot double, to dramatic rather than comedic effect. Fred tries to tell him that he must have known, deep down, but Wesley says that he was in fact absolutely sure he was killing the real person. That's what happens when you threaten to hurt Fred.
** And who was it a robot double of? Wesley's ''father''.
* There was a variation in ''{{Spooks}}'' once (season 2 episode "I Spy Apocalypse"), where the guy the hero shot was real (and human), but the gun turns out to have been rigged.
* ''Series/StarTrekDeepSpaceNine''. When Worf realizes General Martok is suffering from post-traumatic stress disorder as a result of his imprisonment, he [[ChallengingTheChief challenges Martok's leadership in the Klingon tradition]], then lets him win the subsequent knife fight. Reinvigorated, Martok rallies to his command and saves the day. Later, knowing that Worf lowered his guard deliberately, Martok asks how Worf knew he wouldn't kill him. Worf replies simply, "I didn't". The general is so impressed he officially adopts Worf as a member of his House.
* In the ''Series/WhiteCollar'' season one finale, Peter shoots [[spoiler:Fowler]] in the chest to stop him from shooting [[spoiler:Diana]]. When [[spoiler:Diana]] asks how he knew [[spoiler:Fowler]] was wearing a vest, he responds with this.
** The MoralDissonance is averted, however; the "victim" in this case? [[spoiler:CorruptCop SmugSnake Fowler, who's pulled [[MoralEventHorizon more than enough crap]] to qualify for a bullet]].
* In the ''Series/DoctorWho'' episode "Amy's Choice", The Doctor, Amy, and Rory are trapped between two dream worlds, and have to work out which is the dream and which is reality so that they can free themselves by dying in the dream world. After Rory dies, Amy decides to kill herself and the Doctor in that world. They all wake up in reality, and Rory asks Amy how she knew the world he died in was the dream world...
* A variant in ''Series/{{Bugs}}'' happens when the team's weapons expert is wired with a bomb to force him to act as a sniper to remove someone for the BigBad. While the tech specialist is trying to disarm it the BigBad realizes he's not going to make the shot and moves to kill the target himself. The weapons expert pulls away from the tech and kills the BigBad, then the tech removes a chip from the bomb and it deactivates. Cue the tech being lambasted for taking so long and replying that she just removed anything, choosing probably being blown to bits over certainly being.
* In one episode of season nine of ''Series/{{Smallville}}'', Oliver Queen is standing on a podium which has been rigged to blow when he steps off. Clark arrives towards the end of the episode, having learned that [[spoiler:the bomb was fake]] only to find that [[spoiler:Oliver has already stepped off the podium]]. How did he know? [[WhamLine He didn't]], and instead waited until the room was clear so that he could [[spoiler:attempt suicide.]]
* ''Series/KaizokuSentaiGokaiger'', "The Amazing Silver Man" The crew accidentally stumbles upon an Action Commander planting a bomb to blow up the city and demands to know how they knew his plans. They didn't, [[YouJustToldMe he just told them.]]
* ''Series/PowerRangersJungleFury'' has this in "Arise the Crystal Eyes"; after Red Ranger Casey pulls a BigDamnHeroes moment to save the other rangers from Grizzaka, a very powerful [[TheStarscream Starscream]] that had successfully taken the post of BigBad at that point. Casey asks White Ranger Dom for his Rhino Morpher, and attempts to merge it with his own weapon, succeeding flashily.
-->'''Dom''': Hey! How did you know that would work?
-->'''Casey''': I didn't know until now!
* In ''Series/OnceUponATime'', there is a point where Emma accidentally alerts an ogre to their presence and she eventually finds herself on the ground with a very large ogre roaring in her face (imagine the breath on that thing!)- suddenly there's a sharp whistle which distracts the ogre, and the following scene occurs:
-->'''Mary Margaret (aka Snow White):''' [[MamaBear (angrily)BACK. AWAY. FROM. MY. DAUGHTER!]] ''(aka Emma)''
-->(she pulls an arrow from her quiver and fires, striking the ogre in the eye- it promptly drops dead)
--> ''*beat*'' You have to shoot them in the eye.
-->'''Emma:''' (Impressed) When was the last time you shot an arrow?
-->'''Mary Margaret:''' ''(casually)'' 28 years ago. Guess it's like riding a bike.
-->'''Emma:''' Yeah, but how did you know you could hit that?
-->'''Mary Margaret:''' I didn't.
* In the ''Series/{{Supernatural}}'' episode "Taxi Driver", Sam's attempt to break Bobby out of Hell is interrupted by a duplicate Sam trying to pass himself off as the real one in the confusion. After Bobby kills the false Sam, Sam asks if Bobby knew it was the fake, and Bobby admits that he had to guess.
* Implied in the ''Series/BabylonFive'' episode "Spider in the Web":
-->'''Ivanova:''' Well, you know how I feel about telepaths.\\
'''Sheridan:''' Do I ever. You threw one out of a third story window on Io.\\
'''Ivanova:''' There was an ample pool below the window.\\
'''Sheridan:''' [[IllPretendIDidntHearThat I'll assume you knew that.]]
* Subverted in ''Series/{{Farscape}}''. Villains force Rygel to ShootYourMate, but as it's BigBad-[[HazyFeelTurn turned-ally]] Scorpius, this doesn't bother him much.
-->'''Scorpius:''' How did you know I was wearing body armor?
-->'''Rygel:''' I wasn't sure, but... Not so bad for me either way.
* In the ''Series/{{NCIS}}'' episode "Chimera," an incident involving a top-secret naval ship and Russian pirates ends with a missile blowing up the ship and killing the pirates after Team Gibbs has escaped. As the team wonders how the U.S. Navy knew that they'd gotten off the ship, Gibbs says, "I don't think they did."
** In "Baltimore", Tony flashbacks to when he learned his partner was dirty. When Gibbs shows up, Tony name drops the first half of this trope while Gibbs does the second, adding on, "I had a hunch."
* ''Series/{{Leverage}}'': In "The Snow Job", Parker jumps from a second storey window onto Eliot who catches her. He asks for warning next time and then adds "How'd you even know I'd be here?". Parker replies "I didn't".
* ''Series/InspectorGeorgeGently'': This exchange between Bacchus and Gently at the end of "Son of a Gun (after Gently has faced down a Sten gun wielding skinhead):
-->'''Bacchus:''' How did you know the gun wouldn't work?\\
'''Gently:''' I didn't.
* ''Series/{{Wizards of Waverly Place}}'': In the episode "Wizard For A Day", Alex gives Jerry Merlin's hat as a birthday present which can grant wishes for one day, much to Justin's jealousy. She later makes an even bigger present by using the hat to transform the Substation into her father's childhood smoothy place which completely changes the family business. Unfortunately, the reopening of the smoothy place attracts the attention of {{Human Aliens}} who want to steal the place for themselves. Justin (unintentionally) saves the day by using one of the aliens' laser guns to shoot at Merlin's hat, transforming the smoothy place back into Waverly Substation and forcing the aliens to retreat.
-->'''Alex:''' How did you know that shooting at Merlin's hat would reverse all of dad's wishes?
-->'''Justin:''' I didn't. I was just really sick of that present.
* In the ''Series/Daredevil2015'' episode "In the Blood," Karen Page goes to an auction where Union Allied assets are being auctioned off. While she's there, Ben Urich sits down behind her and tells her to avoid looking suspicious by bidding on some of the smaller lots. When they reconvene at the diner that they'd had a meeting at earlier in the day, Karen asks Ben how he knew she was there, and Ben replies, "I wasn't looking for you."
* Combined with TheTapeKnewYouWouldSayThat in this little excerpt from ''Series/MontyPythonsFlyingCircus'', involving two ladies watching the television:
-->'''TV Announcer:''' Well, it's just after eight o'clock, and time for the penguin on top of your television set to explode.\\
''[The penguin on top of the television set does, indeed, explode]''\\
'''Lady #1:''' How'd he know ''that'' was going to happen?\\
'''TV Announcer:''' It was an inspired guess.
* ''Series/RedDwarf'': In "Can of Worms", Lister, Rimmer and Kryten are hunting shape-shifters when they are approached by the Cat. Lister (who is temporarily emotionless) blows him away without a second thought, revealing him to be a polymorph. Rimmer asks how he knew he wasn't the Cat, and Lister calmly replies "I didn't".
* In ''Series/TheThickOfIt'', Hugh Abbott accidentally sends an e-mail saying "Christ! What a cunt!" to a little girl using Terri's PC. Terri calls him out on this, claiming that she saw him use the PC. Hugh promptly admits that he did send the e-mail, before Terri says that she was bluffing and she didn't see them. Hugh then [[BlatantLies says that he knew she didn't know, and was only admitting because it was the right thing to do.]]
* Happens in the ''Series/CHiPs'' episode "Quarantine". A boy with a pipe bomb holds the station hostage before collapsing from a mystery ailment, resulting in the titular quarantine. The quarantine also prevents a bomb squad from entering to take care of the pipe bomb. While Grossman fruitlessly tries to get the bomb squad to come in, Harlan (who hasn't been told of the situation) casually walks in, picks up the bomb, and opens it. It turns out to be just a carrying case disguised as a pipe bomb. When Getraer asks him how he knew it wasn't a bomb, Harlan yelps and drops it.

[[folder:Newspaper Comics]]
* [[http://dilbert.com/strips/comic/2010-12-29/ Alice]] in ''ComicStrip/{{Dilbert}}'' deduces that a coworker must either be an unhelpful moron or a robot sent to destroy the company from within, and proceeds to tear his (robotic) head off. Dilbert asks how she knew it was the robot-option...

[[folder:Video Games]]
* The player gets an opportunity to have his own How Did You Know? moment in the (chronological) beginning of ''VideoGame/MaxPayne2TheFallOfMaxPayne''. No game mechanic prevents you from killing an innocent bystander at a crime site, a cleaner. In fact, you will be rewarded for doing so by him not leading you into an ambush.
** Max himself gets one when he [[spoiler:shoots his partner when she confronts him and his fugitive love interest.]] Only later does he actually find any evidence that [[spoiler:she was going to kill them both by order of the big bad.]] Max, ever the melodramatic sort, states that thinking for even a moment that the future revelation justified his prior actions damns him just that much more.
* A similar example in ''VideoGame/DeusEx''. If you kill a [[spoiler:doorkeeper at the gates of the cemetery housing Dowd's crypt]] on sight, the guy will later turn out to be a spy, and [[spoiler:Dowd]] will even praise you for being just the right type of trigger-happy paranoiac they need.
** ''[[VideoGame/DeusExHumanRevolution Human Revolution]]'' has a similar case where one way to complete a sidequest is to knock out or kill two drug dealers, but gives a special response if you had done so already after being given their names (unlike Dowd, though, Tindall just thinks you're overly violent).
* ''VideoGame/AssassinsCreedI'' had Al Mualim and Altair using almost these exact words during one of their discussions. Al Mualim asking and Altair answering.
* The popular gamemode for the ''VideoGame/HalfLife2'' mod ''VideoGame/GarrysMod'' titled "VideoGame/TroubleInTerroristTown" revolves around trust/mistrust in a town full of terrorists, 1 in 5 of which are united traitors, seeking to kill the innocent terrorists, similar to the Mafia game people play on forums/IRC/at social gatherings. Occasionally someone gets shot for no real reason, or are accidentally pushed off a high ledge or get just plain unlucky and die suddenly when they're a traitor. The result is an upset traitor, and a confused, but happy group of innocent terrorists who have one less threat to deal with. Especially funny when playing with friends who you actually know, rather than random players.
* In ''VideoGame/TownOfSalem'', Jailors and other town killing roles can do this by randomly killing other townies, and ending up killing an evil role.

* [[http://www.egscomics.com/?date=2003-06-27 Set up here]] in ''Webcomic/ElGoonishShive'' (the full exchange doesn't come until the next strip):
-->'''Mom:''' You've brought ''boys'' over, Susan?\\
'''Susan:''' No, Mother, just this one. The other two are girls; they're checking out our TV.\\
'''Justin:''' Hi.\\
'''Mom:''' I'm not comfortable with him spending the night here, Susan.\\
'''Susan:''' Don't worry, Mother. He's ... gay. He's gay, so he won't try anything with me.\\
'''Mom:''' Ugh... men who like men... [[DoesNotLikeMen pure insanity]]. Fine, he can stay. Maybe his homosexuality will rub off on you, and you'll find yourself a decent woman. I'll leave the lot of you alone now... I'll be upstairs.\\
'''Susan''' (thinking): Hehe... she bought it...\\
'''Justin''': So... how'd ''you'' know that I'm gay?
* (Dis)honorable mention to Vaarsuvius from ''Webcomic/TheOrderOfTheStick'', who killed [[SmugSnake Daimyo Kubota]] without an afterthought due to some assumptions without actually knowing petty details like Kubota's crimes or even his ''name''. [[http://www.giantitp.com/comics/oots0596.html Here]].
** A comical version done [[http://www.giantitp.com/comics/oots0259.html here]].
* ''[[http://zudacomics.com/the_night_owls Night Owls]]'' #134, Ernie asks Bill how he knew Louie's magical gaspipe was inert. Bill doesn't know what he's talking about.
* [[http://www.explosm.net/comics/2481/ This]] ''Webcomic/CyanideAndHappiness'' comic.
* Now-defunct SonicTheHedgehog sprite comic ''[[http://www.themysticalforestzone.com/Kajin/insonicnia.htm InSONICnia]]'' has a story where an evil version of Sonic comes to the main universe. Eventually, he angers Shadow, who kills him, leading to this exchange:
-->'''Knuckles:''' But how did you know it wasn't the real Sonic?\\
'''Shadow:''' That wasn't the real Sonic?

* In ''{{Website/Neopets}}'', at the end of The Faeries Ruin plot, [[spoiler:Brynn]] asks [[spoiler:Hanso]] how they knew that Fyora would [[spoiler:be able to reverse his petrification.]] Said character answers that they didn't; it was a "lucky break".
* ''Literature/WhateleyUniverse'': In Diamonds Are a Vamp's Best Friend (Part 2), when Bova was shooting a goon with a gun she just picked up:
--> “Oh. Capture Gel,” I said. “But how did you know that it was that, and not a shotgun or a flamethrower or even a grenade launcher?”
--> “I didn’t,”

[[folder:Western Animation]]
* In ''WesternAnimation/TeenTitans'' episode "Betrothed":
-->'''Cyborg''': (''after Beast Boy just turned into an alien that he saw earlier in the episode'') How did you know that you could do that?
-->'''Beast Boy''': (''having transformed back'') Lucky guess.
* In a ''WesternAnimation/XiaolinShowdown'' episode where Kimiko is fighting an [[RobotMe evil robot duplicate]], Omi jumps high in the air and takes one of the Kimikos out in one swipe. The defeated robot explodes, but, when asked about how he knew which one was which, Omi admits to having guessed. Not quite as extreme as the page description otherwise implies, since if he'd kicked the real Kimiko, she'd have probably just rubbed her kicked spot and been annoyed... not actually exploded.
** This really surprised Clay and Rai though because up until that point, Omi knew ahead of time every trick thrown at him throughout the episode, including Rai's [[RunningGag constant attempts through Shen-Gong-Wu battles and card dealings]]. When he said that he "guessed" that time, they were aghast he didn't/couldn't use his Tiger Instinct.
* ''WesternAnimation/TheSimpsons'':
** The Halloween episode "Dial 'Z' for Zombie", Homer shoots an undead Ned Flanders (this is reported to be Creator/MattGroening's favorite scene from the entire history of the series).
-->'''Bart:''' Dad! You killed the zombie Flanders!\\
'''Homer:''' He was a zombie?
** Another example from another Halloween episode:
-->'''Grampa:''' ''(holding a hammer and stake)'' "Quick! We must kill the boy!"\\
'''Marge:''' "How do you know he's a vampire?"\\
'''Grampa:''' "He's a vampire!?" ''(runs off screaming)''
* ''{{WesternAnimation/Futurama}}'' "The Deep South", the ship is sinking and taking on water. Fry rushes offscreen, we hear a toilet flush, and the water starts to drain away.
--> '''Leela''': "Fry, you did it!"\\
'''Fry''': [''reenters, zipping up pants''] "Did what?"
* ''WesternAnimation/MegasXLR'': "The Driver's Seat" Coop accidentally teleports his Big Glug into a critical component of the Glorft mothership.
--> '''Gorrath''': "How did that primitive know where to hit us?!"
* ''WesternAnimation/RobotChicken'': In the ''WesternAnimation/YellowSubmarine'' meets ''Film/TheHuntForRedOctober'' [[http://video.adultswim.com/robot-chicken/ping-them-back.html sketch]], Ringo didn't know the hole would stop the missile from hitting the Blue October; he was still on acid and said whatever came to him.
* The ''WesternAnimation/WingCommanderAcademy'' cartoon had an example where, faced with a Kilrathi carrier, the commander decides to play chicken with it. This works, and the carrier retreats.
--> Recruit: "How did you know that they would retreat before we rammed them?"
--> Commander: "I didn't."
* In ''WesternAnimation/AmericanDad''
-->'''Roger:''' How did you know I was fireproof? Even I didn't know that! Wait, did you know? I'm going to assume "yes" to preserve the friendship.
** Again in "When a Stan Loves a Woman." At the shooting range, he and a mysterious woman simultaneously shoot each other. Cut to a restaurant:
-->'''Stan:''' So how did you know I was wearing a vest?
-->'''Woman:''' I didn't, but I have a rowboat, so it's easy for me to dump stuff. Did you know about mine?
-->'''Stan:''' No, I was composing your suicide note when you stood back up!
* In part 2 of the pilot for ''WesternAnimation/MyLittlePonyFriendshipIsMagic'', the main characters are attacked by a manticore. They fight back until [[FriendToAllLivingThings Fluttershy]] calls for them to stop, much to their surprise. She approaches the monster, nuzzles it, and the manticore reveals the source of its fury: a thorn in its paw. After she removes the thorn, the manticore lets them pass. Twilight Sparkle asks how Fluttershy knew about the thorn, and the pegasus replies that she didn't, but assumed the manticore just needed to be shown kindness.
** In the ''[[WesternAnimation/MyLittlePonyEquestriaGirls Equestria Girls]]'' movie, when Twilight is about to tell her humanized friends why she's in their world, [[CloudCuckoolander Pinkie Pie]] accurately guesses why she's in their world. When Twilight asks her how she knew that, she answers "Just a hunch."
* This exchange from ''WesternAnimation/FamilyGuy'' after [[LovableSexManiac Glenn Quagmire]] saves a woman who is having a heart attack while changing at the mall:
-->'''Woman 1:''' That was amazing!\\
'''Woman 2:''' You saved her life!\\
'''Woman 3:''' Thank God you know CPR!\\
'''Quagmire (confused look):''' What the hell's CPR?
** Also the basic frame of this trope is present in a joke in the (same) episode where Peter is blind. After Peter saves Horace from a burning building he is asked how he found the courage to risk his life inside said burning building, to which Peter responds "That freaking place was on fire?!"
* ''WesternAnimation/ScoobyDooMysteryIncorporated'' "The Dragon's Heart"
-->'''Mr. Blake:''' But how did you know she would step in the middle of the boat?
-->'''Fred:''' I didn't. That's why I set up traps all over this place!
* In ''WesternAnimation/{{Archer}}'':
-->'''Archer:''' ''(calls Ray on his cellphone, then snaps a picture of a bomb in his mother's work desk)'' I need you to help me...\\
'''Ray:''' ''(instantly)'' Blue and yellow.\\
'''Archer:''' You mind looking at that for more than a half-second?\\
'''Ray:''' I wired the damn thing. Ass.\\
'''Archer:''' Well, I didn't know that. Ass. ''(clips wires)''\\
'''Ray:''' Holy shit, you actually did it? I was lying.
* In the first episode of ''WesternAnimation/ClerksTheAnimatedSeries'', after Dante and Randal thwart Leonardo Leonardo they realise they forgot to blow up his convenience store. Cue Leonardo's convenience store blowing up and Jay and Silent Bob walking from the wreckage.
-->'''Dante:''' How did you know about the plan?
-->'''Jay:''' What plan?
* ''WesternAnimation/TheSecretSaturdays'': Happens in "Black Monday" when Drew attempts to shoot her MirrorUniverse counterpart in the face with the Claw, only to have her doppelganger parry it with her prehensile tongue.
-->'''Zak:''' How did you know she could do that?
-->'''Drew:''' I didn't. I just wanted to hit in her in the face.
* In the first episode of ''WesternAnimation/DuckTales1987'' when the Beagle Boys threw a stage curtain at the Nephews triggering the trapdoor underneath.
-->'''Huey:''' How'd you know there was a trapdoor there, Dewey?
-->'''Dewey:''' I didn't.
* ''WesternAnimation/UltimateSpiderMan'' "Blade"
--> '''Spider-Man:''' I see what you're doing. You sent [[ComicBook/LukeCageHeroForHire Power Man]] to punch a hole because you knew his invulnerability would protect him, right?
--> '''Blade:''' He's invulnerable?
* Zig-zagged in Creator/TexAvery's "Dog Hounded," where Droopy proceeds to flummox the Wolf by being where he isn't supposed to be.
-->'''Wolf:''' How did ya get here, anyway?!
-->'''Droopy:''' Now, let's not get nosy, bub.
* Invoked in ''WesternAnimation/TheBatman'' where Batman punches an old lady florist (actually a PlantPerson guarding Poison Ivy's lair.) Batgirl is surprised Batman knew she was a fake. Batman is [[TheStoic silent as usual]] as Batgirl continues questioning.
* In ''WesternAnimation/JohnnyBravo'', we have the fictional action star [[TheAhnold Squint Ringo]]. In one of his movies, after killing an entire [[GirlScoutsareEvil army of killer robot girl scouts]], the following exchange take place:
--> '''Mayor:''' Thank you for saving our town kung-fu guy. But how did you know they were robots?
--> '''Squint Ringo:''' Robots?
* ''WesternAnimation/RandyCunninghamNinthGradeNinja'': Back when Randy and Howard were six-year-olds, they snuck into Norrisville High so Randy could prove to Howard that the Ninja exists. Randy turned Marci back to normal by cutting her apron. When the Ninja of 2005 asked him how he knew it'd de-stank her, Randy said he was aiming for her head. The Ninja of 2005 then hoped Randy would never become the Ninja.
* ''WesternAnimation/BatmanBeyond'': Bruce is telling Terry about an incident from his days as Batman:
-->'''Terry:''' How did you know Robin would get there in time to save you?\\
'''Bruce:''' I didn't.\\
'''Terry:''' Then for all you knew, you were walking into a trap with no way out.\\
'''Bruce:''' [[TrapIsTheOnlyOption Sometimes you have to.]]
* ''WesternAnimation/TheHairBearBunch'': In "The Diet Caper," Hair's alibi for the animals raiding Peevly's refrigerator is because it was Botch's birthday. Peevly grudgingly buys it and orders the bears to clean up the kitchen.
-->'''Bubi:''' Boy, it's a good thing you remembered Botch's birthday, Hair. That was a real (''unintelligible''). You saved our necks.\\
'''Hair:''' Who remembered? I made it up.\\
'''Square:''' You're joshin'!\\
'''Bubi:''' Yeah, but Botch didn't blow the whistle on you.\\
'''Hair:''' How could he blow the whistle? ''He'' doesn't remember when his birthday is either!
* WesternnAnimation/DangerMouse tricks the Demon of the Fourth Dimension ("Demons Aren't Dull") into returning him and Penfold to their own dimension by invoking a clause in the Demons' union rule book:
-->'''Penfold:''' Lucky you remembered those union rules.\\
'''D.M.:''' No, Penfold. Lucky ''he'' didn't. I made them up. I fooled him.