Mind-Blowing

What’s the most mind-blowing, world-changing book you’ve ever read? (Or article, poem, whatever.)

Don’t forget to leave a link to your actual response (so people don’t have to go searching for it) in the comments—or if you prefer, leave your answers in the comments themselves!

And also–don’t forget, folks–sometimes WordPress’s spam filter seems to decide that a lot of perfectly valid answers are spam. I periodically check throughout the day for lost comments. But, PLEASE–if your comment doesn’t show, don’t post it four more times in the hopes that one of them will go through. I get very, very tired trying to sort out the duplicates (grin).