What's a book you were required to read in school that you're happy you read?

Mmmm.....most of the books I had to read for school were quite disturbing and adult/graphic. I think the one book I was glad I read was to Kill a Mockingbird. I think it was an important book that helped me understand the extent of racism better. I was also glad when we were assigned certain sections of the Bible because I read it and realized the Bible was insane. Lol