> because most kids either aren't mentally developed

I've gone back and read so many books I was supposed to have read in HS and college. I don't think at the time I had the life experience to fully grasp many of the message(s). It's one thing for a teacher or guide to explain in abstract the underlying messages, it's another to have dealt with them in your own life and see yourself in the characters [1].

[1] I always read like I'm one or more of the characters and not simply an observer.