Let's make this a more collaborative post about literature. I'd like to hear about the books, either good, or bad, or seemed good at the time, or superb, or mildly embarrassing, that you feel had a significant role in shaping the person you became.
Me, I write about a lot of books, and will natter on recommending The House of Mirth until the end of time (read The House of Mirth!), but it's, um, definitely The Lord of the Rings that has, historically, mattered more to me than any other book. That's just how it is. I read it, myself, for the first time in second grade. And I still read it, about once a year. When my brother and I were little, my father read the entire thing aloud into a cheap tape recorder (and about forty tapes) so we could listen to it on car trips. And, generally, when I meet another person who takes Tolkien way too seriously, I know I'm going to be able to understand them.
Sometimes, when you revisit those books, they don't work anymore. Or they might not work anymore, so you choose not to re-read them. My father refuses to re-read In Watermelon Sugar, which had a massive impact on his life, because he knows it's going to be depressing. I have been on a ten-year John Irving hiatus, because I'm pretty sure that A Prayer for Owen Meany is going to seem hokey now, but it was very important to me at thirteen.
So, let's hear it.