I Know Kung Fu - Television Tropes & Idioms

...We're doomed.

Neo: I know Kung Fu.

Morpheus: Show me.

—The Matrix

Keanu Reeves: I know Kung Fu.

Alex Trebek: For the last time, no, you don't.

—Saturday Night Live, Celebrity Jeopardy

How did a character suddenly acquire a needed skill?

By an unrelated previous life experience he never knew would prove so useful, sometimes a Ret Con. In other words, the character always had the skill, but You Didnt Ask.

A character who is an actor is a sharpshooter because he had to learn it for a role. A writer is an expert on medieval history because she had to research it for a book.

Common with older, gray-haired characters. You never think that your mother or grandmother could've had a life before you were born.

The name of this trope comes from an oft-parodied scene in The Matrix, where Neo gets Kung Fu and other combat skills programmed into his head. (Though note that it's status as a Stock Phrase was already ancient then.) In a case like that, though, you're actually dealing with an Upgrade Artifact.

Combine this with Character Development to get Taught By Experience and Took A Level In Badass.

See also I Know Mortal Kombat, Taught By Television. Not to be confused with I Know Karate.

Compare New Powers As The Plot Demands, where not even the character knew that he had the new skill all along.

See also Deus Ex Machina, a similar and often related concept

Examples:

Anime and Manga

Sort of played in Suzumiya Haruhi, where Yuki suddenly shows up some awesome guitar skills that could leave Slash, Eddie Van Halen, and Buckethead shocked. Kyon, of course, makes some snide remarks about how she learned such techniques.
- Not to mention that Haruhi suddenly has the voice of a well-trained 25 ~18-year-old. But then, this trope is justified in both cases, as Haruhi is voiced by Aya Hirano, and Yuki is Yuki.
One of the goals of Kirika in Noir is learning where she gained the skills of a master assassin.
Parodied by Tristan in Yu-Gi-Oh The Abridged Series; though he himself is a hapless bumbler, he claims his voice knows kung fu, as well as giving him super strength.
In Death Note, L and Light both somehow have pretty good hand-to-hand combat skills. L's skill is somewhat Retconned in Another Note, a novel that takes place before the story. Light we just assume has every skill necessary at the moment. He tends to have that. Oh! Watari's also a sharpshooter! When the *** did that happen?!
- Duh, these are obviously cases of Awesomeness By Analysis and Battle Butler, respectively.
- And, to be fair, he is the personal assistant to the Best. Detective. Evar. He's pretty much contractually obligated to be a badass with wide variety of useful skills.
In Speed Racer, every member of the Racer family knows martial arts. Sure, Pops used to be a wrestler, but still...
In the Pretty Sammy OAV, Ayeka Takada knows martial arts and isn't afraid to use it, especially against Ryoko when it comes to Tenchi.
~~Wilford Brimley~~ Dr. Reichwein of Monster used to work with the border police, but the two punks trying to beat him up in an alley didn't know that.
- Averted with Nina, who was shown practicing Aikido before it came in handy.

Comics

In the Justice League episode "Hereafter", Superman awakens on a wasteland planet with a red sun, robbing him of his powers, with only a city street's worth of objects to assist him. As he attempts to find a way off, the human-level Kal-El displays shocking aptitude in blacksmithing, sword fighting, and even dog sledding as he traverses the blasted landscape.
Dr. Strange comics love this, in the storyline The Oath, Strange's opponent conjures a mystical artifact, that prevents any magic being used for a certain amount of time, thinking himself physical stronger than Strange and able to beat him in physical combat, Strange takes a couple of hits, before turning the tables and revealing that in addition to becoming Sorcerer Supreme, he had become a master at kung fu with help from his assistant Wong.
In Watchmen, several characters' fighting abilities are partially explained by the fact that they are skilled in gymnastics. Whilst this makes sense for, say, Ozymandias, it does seem a little peculiar when it comes to Rorschach, who doesn't really seem the type.
- Rorschach's been boxing since he was a teen. Read the book.
- He also fights very, very dirty.

Film

In the film Three Kings, one National Guardsman is an airport baggage handler in civilian life. Amazingly, during his adventure in Iraq, a situation arises requiring a detailed knowledge of suitcases.
In The Poseidon Adventure, Shelly Winters' character, while seemingly the least fit (and least useful) of the survivors, was able to swim a long distance underwater while carrying the end of a rope, because she was on the swim team in school. Sadly, she dies of a heart attack immediately afterwards.
Kar from the movie Bullet Proof Monk learned literal kung-fu by imitating the constant martial arts films playing at the chinese theatre where he lived.
- Though to be fair, the Nameless Monk quickly demonstrates that the knowledge Kar got that way isn't very useful against someone who actually knows what he's doing.
- And yet Kar instantly becomes Crouching Tiger Hidden Dragon even before becoming the guardian of the Scroll.
This is extremely common in the novels of Michael Crichton. In Jurassic Park, one of the kids just happens to know UNIX (in the movie she claims to be a hacker). In The Lost World movie, Dr. Malcolm's daughter is a gymnast...and there just happens to be pipes to swing from. In Timeline, one of the characters just happens to be an expert free climber, and they have to scale the outer wall of a castle. And so on.
Small Town Indiana resident Tom Stall is far to good at hurting people than any coffee shop owner has any buisness being.. Morbidly, it turns out there is A History Of Violence behind his skills.
In Atlas Shrugged Dagny flies an airplane when she goes searching for John Galt. It is never mentioned why or how she knows how to fly.
In My Blue Heaven, Vinnie is a gangster who (comically) portrays himself as afraid of and unskilled with guns, but in the final shootout proves to be an excellent from the hip marksman.
Barney: You said you didn-
Vinnie: I Lied.
In Demolition Man, Sandra Bullock's character abruptly acquires high-kicking combat skills (in a society where even high-fives are considered too violent). Asked where she learned it, she replies, "Oh - um, Jackie Chan movies."
In the film Three Amigos, Ned Nederlander managed to win in a quickdraw against a german weapons smuggler, because he had learned to be the fastest draw for his movies. The German in question was actually a huge fan of Ned's who learned to be a master shot by watching his old movies and copying them. Thinking Ned had been using trick photography to only look that fasst, he challenged Ned, and lost.
A literal example in Brotherhood of the Wolf. Until the last part of the movie the protagonist is presented as a Badass Bookworm, a biologist who is competent with guns too, but it's his sidekick Mani who shows his skills as a superb martial artist. After Mani is killed, the hero, all alone, raids the hidden base of the bad guys and kills a shitload of them - showing that he does, in fact, know Kung Fu too. Hey, maybe he didn't feel like showing off until Mani was around.

Literature

All right, this particular trope page has been around for three and a half years and no one thought to mention Sherlock Holmes and his unestablished mastery of "baritsu", which enabled the ultimate Authors Saving Throw. How does a thing like this happen?

Live Action Television

In Buffy The Vampire Slayer, Xander (once mentally turned into a soldier by a spell) knows the layout and lingo for the local military outpost. When these turned out to be useful, the writers Hand Waved them away... and Xander didn't even tell us about that until months after his implanted memories were gone.
- In the seventh season, the writers seemed so desperate to justify Dawn's very existence that she suddenly could translate old magical books from sumerian. It was slightly less justified than the same character demonstrating sword proficiency in the last episode of the sixth season. At the time, she at least said she learnt that by watching her sister fight demons.
In Charmed, despite Phoebe Halliwell having trained in martial arts, the third season shows auctioneer/photographer Prue Halliwell surpassing her in martial arts skills she has never learned.
- Also in Charmed in "That Seventies Episode", Phoebe suddenly reveals the ability to pick locks. Lampshaded by Prue, who rhetorically asks, "Why am I not surprised that you know how to do this?"
Catherine, typically the classiest and snootiest character on News Radio, nonetheless knows a little three card monte from a summer spent hustling with an uncle.
- Dave Nelson also has a surprising amount of skill in both knife throwing and tap dancing.
  - Catherine Duke is a poor man's Dave Nelson. Dave Nelson also just so happens to be a ventriloquist, speaks Spanish, is an expert at the arcade game Stargate [Defender], can sing a cappella, and can cross dress surprisingly well.
Diane on Cheers was an excellent bowler because she had taken bowling for her PE credits in college.
Quantum Leap's Dr Sam Beckett has seven degrees (most of them unidentified) and knows eleven languages. On the other hand, the Time Travel process leaves his memory swiss-cheesed, so he can forget as well as remember things as needed by the plot. Also, any skill he doesn't have can be taught to him by Al, who has been an astronaut, a boxer, a stage actor, a baseball pitcher, and even teaches Sam how to out-draw an old West gunslinger. In fairness, if you were looking for someone to be a holographic observer you'd probably want to get someone who is pretty handy, especially since they can't physically help. And Al is clearly old enough to have been all these things.
- Al has also been married five times, and when information he gives Sam seems too arcane for even Al to have personally experienced, he often claims he learned it from one of his ex-wives.
- There was an episode where Sam, in a life-threatening situation two switchblade-wielding kidnappers/rapists, was able to fend off his attackers WITH KUNG FU! After high kicking one of the scumbags, Sam was surprised to learn that he could do that, immediately after which Al informed him that he was skilled in several schools of martial arts.
It's even in reality TV: In the Survivor All Star episodes, shortly after Richard Hatch gets voted off, we find out that Lex has a talent at fishing (which we never knew from Survivor Africa, because the only water Lex encountered there was at the bottom of a muddy hole).
In Lost, several characters have developed useful skills that have proven critical on the Island. Sun's knowledge of the medicinal qualities of herbs found on the island exceeds those of a normal home gardener, and Kate's "tracking" skills came out of nowhere (explained by a You Didnt Ask). However, this may be still explained by the mysteries of the island.
Shepherd Book of Firefly displayed an array of crime-related talents and knowledge that one wouldn't expect the average priest to have, hinting at a Mysterious Past; however, it was never made quite clear what this past was, beyond being former Alliance and his survival being very important to the authorities (except possibly non-canon Serenity book tie-in, where he reveals to Mal that he is a former Operative).
- The Serenity RPG has characters buy their skills as they go, the justification being that we find some new facet of the character's backstory at that point.
- Word Of God has said that's canon now, as "Book" is actually the name of someone he killed.
On Friends, Chandler has hidden from Monica that he's an excellent ping-pong player, because he didn't want her to enter them in doubles tournaments. When she hurts her hand during a game, he turns out to be a not-so-hopeless replacement.
Chuck gets this after uploading the neo-Intersect into himself. He even quotes the trope name.
Justified with Sandra Bennet of Heroes. She can make fake I Ds, a skill she used to sneak into Def Leppard concerts when she was younger.

Video Games

The computer game Planescape Torment gives us The Nameless One, an amnesiac immortal (or is it immortal amnesiac?) who, rather than learning skills from people that he meets, instead remembers whatever skill it was that he forgot, that, occasionally, he taught the teacher ages ago. It goes a step further by having you relearn skills by re-attaching severed body parts that you had already grown back, which involves re-severing them. And one of them is your eye.
Jennifer from Disgaea utilizes this trope quite literally.

Western Animation

Hey Arnold!, "Road Trip": See Broken Streak for details on Helga's mom riding bulls.
In one episode of Kim Possible, Dr. Drakken hypnotizes all the senior citizens in Florida, including Kim's Nana, who it turns out has had quite an interesting life and picked up an assortment of skills, including piloting, race-car driving, and of course, martial arts.
- Also, Kim's sidekick Ron is magically imbued with powerful "Monkey Kung Fu" skills, though typically he can only use the skills when he's not actually trying to or angry.
  - Or evil.
Winx Club had fashion-obsessed Stella solve a puzzle in one episode by remembering a minor detail from a field trip they took for magical history class. (It should be noted that this is a dub change: in the original, it's her love of fashion that helps her solve the puzzle, although with this method she essentially stumbles on the solution.)
The Boondocks. Who knew Uncle Ruckus "had mastered the ancient and deadly art of the nunchaku".
Bart spontaneously learns French in an early episode of TheSimpsons just by hanging around French people. Possibly justified because, as Skinner points out in the same episode, total immersion is a good way to learn a language quickly.
- It's possible that Bart is a language prodigy and no-one knows it yet. In the episode when they went to South America, Bart became fluent in Spanish by listening to a Spanish tape for a few hours. Of course, at Homer's behest he intentionally forgets it.
- Similarly, in the episode where the Simpsons end up in Japan, both Bart and Homer learn to speak Japanese fluently after spending somewhat less than four hours in a Japanese jail cell. They also get taught how to perform a tea ceremony. This is apparently part of the Japanese "prisoner rehabilitation programme" though...

Web Comics

In Harkovast, Chen-Chen at first seems pretty helpless, but is suddenly revealed to be a master of the sliding mountain style, which allows her to kill armed opponents with her bare fists.

Real Life

How can we forget the excellent, real life example of Uwe Boll, the German film director who challenged his many critics to a boxing match. Turns out he was a semi-professional boxer before taking up direction and beat the ever-loving snot out of the 4 (?) critics who went into the ring with him.
- It should be noted that Boll openly cherry picked his opponents, choosing the ones least likely to put up a real fight (including Something Awful's Lowtax). When he realized that Seanbaby would give him a real fight, he called the whole thing off.
- To clarify further, Seanbaby is about a whole head-and-maybe-the-shoulders-too-if-it's-a-Monday taller than Uwe Boll, and knows Muay Thai.
While filming a scene where Saruman is stabbed in the back, Christopher Lee explained to Peter Jackson that when that happens, the victim doesn't yell. When asked how did he knew, he explained that during WWII, he was in special operations. The story is told in the extras for the Lord of the Rings and you can watch it here.