There are two kinds of people in this world: those who enjoy reading the classics for extra credit, and those who always reach for the CliffsNotes. Luckily for the second type, since coming into vogue the film medium has been selling out theaters with adaptations of classic literature. These movies were lit! Classic lit, that is.
Here's the problem, though. There are only so many well-known classic books whose stories lend themselves to the big screen. You know what they say, there are no new ideas. But a tweak here and a tweak there, a fresh coat of paint, and old concepts can be passed off as new. Just like this introduction paraphrasing Mark Twain's quote here (much less eloquently, of course). If Twain is to be believed, however, we should be a lot more forgiving of all the "gritty" reboots released every year.
The following movies are based on classic books (officially or unofficially), where the premise has been changed just enough that they're not wholly recognizable - but certainly will be to those who know what to look for. Once you know these popular movies were actually based on the books you pretended to read back in high school, feel free to be that insufferable type who tells everyone how much better the book was than the movie.
Remember to vote up the best movies that - whether you realized it or not at the time - were based on classic lit.