I loved LOTR as a kid. All my friends were into it, I loved the movies and the battle scenes. I loved the video games. I loved the books too, but I can't say the process of "reading" them was as enjoyable as I'd like. I think I just wanted to read it to get the full story and say I did it. When I was 14/15 I think I read and reread the Fellowship of the Ring 3-4 times just because I would always get burnt out towards the end and have to start over. It felt like a challenge but one that I wanted to finish.
Flash forward to now. I'm 30 years old, and I never thought it was possible to enjoy reading 25 pages about Hobbit relationships in the Shire as much as I do now.
I'm picking up so much humor and sarcasm that went over my head when I was a kid. Instead of being bored to tears reading the description of every little grassy knoll, I'm now enjoying every word and fully being able to put myself in Middle Earth.
My girlfriend laughs at me because every night she finds me under the covers, listening to the movie soundtracks, and reading LOTR, for hours.
While I knew just how incredible the books were, they're immensely more enjoyable as an adult.