But I Read a Book About It

"Fraser: I did read a flight training manual in my grandmother's library. There were a couple of pages missing, but I'm sure nothing vital... And I'm guessing that there are a lot of similarities between a Sopwith Camel and today's light aircraft."

- Due South

You have a friend, who has never actually done something but hey he/she has read all about the subject so they are going to attempt it anyway. What could possibly go wrong... right?

This trope is the literary equivalent of I Know Mortal Kombat and Taught by Television -- that is, the character in question gets their knowledge by reading about it. Unlike those tropes, however, it's at least plausible for a person to actually be competent when they have to apply their book knowledge in Real Life.

Anime and Manga

 * Eyeshield 21: The Amino Cyborgs team do only a middling amount of training, and spend more time getting juiced up and reading books on how to play football. This leaves them with low stamina and a poor grasp of football fundamentals when they play the Devil Bats.
 * In Noir, the Action Girl Kirika reads a book on making tea and henceforth enjoys it to no end. Which is kinda cute, once you consider that making tea is the only thing she can do well besides killing people, and the only thing she ever learned on her own.
 * Battle Royale uses this for two of Kazuo Kiriyama's Crowing Moments Of Awesome, both in Flash Back.
 * In Pokémon Special, the main reason Platinum went on her journey was to try out first hand the many things she read about. That said, sometimes she initially sucks at whatever she's trying out even when she recites whatever the book told her on the subject, like when she kept falling down when she was on a bike for the first time in her life.
 * Yuu from Holyland first learnt boxing from a book.
 * When Gohan of Dragonball Z has to play baseball in high school, he notes that he has read about it after admitting that he never played it before. Of course, being a superhuman half-alien who spent a sizable portion of his life in Training From Hell, any physical activity is pretty much a cakewalk for him, once he understands what he's supposed to be doing.

Fan Fiction

 * DJ Croft of Neon Exodus Evangelion is suspiciously good at sex, considering he's supposedly a virgin -- he learned the how-to from a book and filled in the gaps with just-that-awesomeness

Film

 * American Beauty.
 * Aliens. Gorman's only been on two real drops. Counting this one.
 * In Three Days of the Condor, based on the novel Six Days of the Condor, Joe Turner's job for the CIA is to read books, newspapers, and magazines from around the world, looking for hidden meanings and new ideas. When the Call to Adventure comes to him, he uses his book learning to survive.
 * In Train of Life, the driver of the locomotive had to teach himself from a book. Actually, it works.
 * In The Flight of the Phoenix, one of the characters says he has experience building and designing aircraft. He later reveals he works with model aircraft, but it turns out the principles are much the same, just on a smaller scale.
 * In the first Short Circuit movie, Number 5 reads everything in Stephanie's house (including the entire encyclopedia) before his adventures. The next day he reads the User's Manual (Not Driver's Training) for Stephanie's van immediately before driving it.
 * A subversion in that he's still an abysmal driver, and nearly gets himself and Stephanie killed several times within a span of a couple minutes. Since he only knew how the car was supposed to work, and not the rules of driving, it's still this trope.

Literature
""Don't worry. I've read all about doing this sort of thing!""
 * In the Discworld novel Wintersmith, Roland believes that he will be an expert swordsman because he has read the fencing manuals and fought many imaginary swordfights in his mind.
 * The Rupert in Monstrous Regiment does the same thing. He actually cuts his own hand practicing out of a book.
 * His sword hand, in fact. Do not ask how.
 * King Verence and Queen Magrat order a lot of text books, too. Misreading the word "martial" makes for all sorts of fun.
 * In Harry Potter, Dolores Umbridge states that just having a theoretical basis in Defense Against the Dark Arts should be enough to prepare the students to successfully take their exams. (In a subversion, though, the real reason for the dumbed-down, book-taught Defense Against the Dark Arts class is to ensure the students don't have any practical knowledge.)
 * Hermione gets a few of these.
 * Scriber Jaqueramaphan from A Fire Upon the Deep by Vernor Vinge; he also tends to be pretty incompetent in most of the things he's read about. Terrifying the hell out of his friend when they're about to sneak through the army of a feared warlord. Scriber is a spy, and is therefore assumed by the others to know what he's doing.


 * David from the novel version of Jumper when he finally loses his virginity. Millie asks if he's really a virgin, and he replies, "I told you, I read a lot." (It's a running gag, the "read a lot" thing).
 * Heinrich Dorfmann in Flight Of The Phoenix instructs the survivors on how to rebuild the crashed plane... even though he's only ever designed model aeroplanes
 * Don Quixote is a very old example; he read tons of books about knights and then thought he could be one.
 * Edward Cullen. While the rest of his family was having housebreaking sex, he was by his lonesome spending his sleepless nights studying everything there is to study. For example, he cooks perfect meals for Bella on his first try, despite never having a reason to cook before.
 * He often Lampshades this fact when he talks about human emotions like jealousy and lust.
 * Horatio Hornblower is constantly reinforcing his Badass Bookworm status by reading. That and the fact that he is very Good with Numbers.

Live Action TV
"Hugh: Right now, Sir Peter, you've never flown an aeroplane before? Stephen: Never flown in my life, Johnny, no. Hugh: And you've never had any lessons? Stephen: Oh I've had lessons, maths, geography ... Hugh: But not in flying? Stephen: No. Hugh: And I've never flown before. Is this something you've always wanted to do? Stephen: Not particularly. So when you rang up I just leapt at the chance. Hugh: Right."
 * In Buffy the Vampire Slayer, Wesley bragged that in the new Watcher training, he had even taken on two vampires "under controlled circumstances, of course". Giles quickly countered that he wouldn't encounter those in Sunnydale... controlled circumstances, that is.
 * Star Trek: Voyager, "Rise." Neelix claims to know everything about orbital tethers (flexible columns going from a planet to an orbiting station, so you can take an elevator to it). He must confess that he really only worked with models. Very detailed models as he's quick to claim, but still models.
 * Parodied with Dave in Flight of the Conchords, who acts like an expert in all things, especially being a ladies' man. Judging by his tendency toward Malapropisms and the way he (deniedly) lives with his parents...
 * X Files: "I play Dungeons and Dragons. I know a thing or two about courage"
 * On The Big Bang Theory, Sheldon Cooper attempted to learn to swim on the internet. And to rock climb.
 * He's actually pretty good at the climbing. It's when he looks down that it all goes wrong.
 * He also tries to find a book on how to make friends. All he can find is a children's book, Stu the Cockatoo is New at the Zoo, but he figures he can interpolate the information to fit his needs.
 * Invoked unsuccessfully in A Bit of Fry and Laurie when they try to fly a plane with no experience, not even reading about it.

"Jemaine: You'd better watch out. Bret knows karate. Bret: Yeah, I've got a book on karate. But I haven't actually read it yet."
 * Taken to its logical extreme in Flight of the Conchords.


 * Manuel in Fawlty Towers. "I speak English well. I learn it from a book."
 * In the All in The Family episode "Edith Writes a Song," Mike tries to placate two African American burglars whom Archie has racially insulted, by explaining that Archie doesn't know what it's like to grow up in the inner city. One of the burglars responds, "Oh, and you do?" Mike sheepishly replies that he learned about it in his sociology course.

Music

 * Read About Love by Richard Thompson would be an inversion: the character portrayed has "read about love" and doesn't understand why he makes girls cry.

Tabletop Games

 * This is actually a knack in Scion. Basically means that the Scion has read so much about stuff they can try them even if they have no training.
 * The Factotum class (dungeonscape) in Dungeons and Dragons has this as it's premise. As a result it's class skills are "All", even obscure class specific ones are treated as class skills for a factotum.

Video Games

 * Pretty much any CRPG will contain skill books for those all important extra skill points.

Western Animation
"Peter: It'll be okay Brian, I read a book about it. Brian: Are you sure it was a book? Are you sure it wasn't...nothing? Peter: Oh yeah."
 * Parodied in Family Guy:


 * My Little Pony Friendship Is Magic, "Fall Weather Friends": Grade-A bookworm Twilight Sparkle enters a big marathon, the Running of the Leaves, alongside her more athletic friends Applejack and Rainbow Dash. The two of them scoff when Twilight claims she's read a book on running techniques in preparation for the race, but in the end she manages a respectable fifth place from pacing herself, while Applejack and Rainbow Dash end up tied for dead last because the two of them were too preoccupied with making sure the other doesn't win.

Real Life

 * The entire reason for the Dummies (Wiley), Complete Idiot's Guide (Alpha Books), Teach Yourself (Hodder & Stoughton), and Everything Guide (Adams Media) series' success, as well as websites like eHow and Howcast. Don't underestimate the value of practice though -- "instinct" isn't.
 * There was a parable in the Eighteenth century about the need for this for a military officer and the fact that street smarts isn't necessarily enough. It goes roughly like this, "There was a mule who served in the army for ten campaigns. At the end it was-a mule."
 * But mules don't learn military tactics by experience on the battlefield; people do.
 * Subversion. According to CS Lewis in The Discarded Image(a series of lectures about the cultural background of Medieval literature) many medieval beliefs, even those that sound like holdovers from primeval superstition were in fact simply because somebody had read a book about them. Books were so expensive and such fine pieces of craftsmanship that no one could really quite make themselves believe that a book could actually be wrong.
 * Among the many lesser-known things the U.S. government habitually does is pay for the creation of (often mind-numbingly) detailed publications and manuals on pretty much any random thing a citizen might need to know how to do. For example, cooking a turkey or safely cutting down an evergreen tree with a chainsaw. Said publications are cheaply (cost of printing and postage) or freely available, especially with the rise of the Internet, and there have been accounts of people (usually in the bureaucracy, who know about them and can find given topics) who learn skills mainly from these.