“But how can we do it if we don’t know what it is?”
“Why blame it all, we’ve got to do it. Don’t I tell you it’s in the books? Do you want to go doing different from what’s in the books, and get things all muddled up?”

– Mark Twain

The Adventures of Huckleberry Finn, Chapter 2. Tom explains to his gang that when capturing prisoners it’s best to keep them until they are ransomed. Because that’s how characters in books do it, he says.