Picture this: it's the late 19th century and you're Robert Louis Stevenson, a struggling Scottish author who's written a number of books about traveling through Europe and the United States. Your parents kind of hate you because, in this conservative day and age (the late 1870s), you've fallen in love with a married woman who is ten years older than you. Her name is Fanny Osbourne, and you are carrying on an adulterous relationship in her hometown of San Francisco. Not only are your folks shocked and horrified by your behavior, but you are sick (you've had a severe lung disease, tuberculosis, for most of your life) and really, really poor. So you need a miracle. That miracle comes in the form of one terrific idea: you decide to write a book about pirates. And fortunately, your girlfriend's son can help you with it.

The idea for Treasure Island came from a map of an imaginary island Stevenson drew with Fanny's son, Lloyd Osbourne. Stevenson took this map and decided to write "a story for boys; no need of psychology or fine writing" (source). Stevenson focuses almost entirely on plot in this book, with very little direct exploration of character's psychology or motivations. We don't know what makes Long John Silver a pirate, we just know that he is one – a darned good one – and that's enough to keep the book going.

This lack of psychological depth makes Treasure Island really different from another of Stevenson's famous books, Dr. Jekyll and Mr. Hyde . But it's also a sign of the audience Stevenson is looking for. He's aiming Treasure Island at kids, who are more interested in cool stuff happening than in intense descriptions of characters' inner selves. Still, even if Stevenson is trying to avoid "fine writing," Treasure Island remains full of observations about human nature and interaction that keep the reader interested in the characters as well as in the story's many twists and turns.

Stevenson originally published Treasure Island under the title The Sea-Cook (referring, of course, to that fabulously tricky pirate Long John Silver) in the magazine Young Folks over a period of several months from 1881 to 1882. It didn't do that well as a series of episodes, possibly because the title is so boring (seriously, who wants to read about a chef on the ocean?). But then Stevenson repackaged the story as a book, Treasure Island, in 1883, and it became a bestseller (source). Stevenson still wasn't exactly a lucky guy (he died young of tuberculosis), but Treasure Island made him famous in both his lifetime and long after his death – not bad for a book that developed out of an idle afternoon's sketching with his girlfriend's son.

We all know what pirates are like: we've seen Captain Hook in Peter Pan and Jack Sparrow in Pirates of the Caribbean. Maybe we've even eaten at chain seafood restaurant Long John Silver's. Pirates sing drunkenly: "Fifteen men on a dead man's chest, yo-ho-ho, and a bottle of rum!" Pirates keelhaul and force their enemies to walk the plank, sending them to the depths of the ocean: "Davy Jones's locker." And pirates shout things like, "Avast!" and "Shiver me timbers." They show nothing but contempt for land-dwellers – "lubbers" and "swabs," the lot of them.

The guy who invented pretty much everything we know about pirates is Robert Louis Stevenson, in a little book called Treasure Island. Oh sure, Stevenson mixes in a lot of real sea language, with his boatswains and coxswains and jibs and bowsprits. But Treasure Island was also key in popularizing a certain idea of how pirates talk – and look, too. Peg-legged, parrot-touting Long John Silver has become everyone's image of a pirate, and we owe it all to Stevenson's gift for language, suspense, and invention. Stevenson is even the one who wrote that song, "Dead Man's Chest" – the title of the second Pirates of the Caribbean flick. So obviously Treasure Island has left fingerprints all over our popular understanding of pirate culture.

Even though Stevenson is writing over two centuries after the so-called Golden Age of Piracy (the era of the most famous real-life pirate ever, Blackbeard and a hundred years after the setting of Treasure Island itself, he still manages to give us a world of pirates that feels real, filled with greed, desperation, cynicism, strange alliances, and charismatic sea-cooks. Over hundred and thirty years after the publication of Treasure Island, Stevenson's fictional world of piracy seems more real than any factual analysis of crime on the high seas. If you've ever spent even a minute dreaming of sailing the ocean blue and digging up gold doubloons, trust us, Treasure Island is the book for you.