I had a similar experience with the play "A Raisin in the Sun". Reading it in class, it was boring and difficult to relate to. Watching the play live as an adult, you realize it's actually hilarious and heart-wrenching.

Part of it is growing up, but part of it is (obviously) that plays aren't meant to be read. There's a lot of detail and tone that doesn't really come across properly, and it sucks the life out of the story. Not sure why it's such a common practice in school.