Same here. Liked the movies, though. Go figure.
I scarfed LoTR down at 15 -- all three books -- in less than a month. I ripped through all 12 of E.R. Burroughs Mars novels in about a semester when I was 17. I recently picked up LoTR and one of the Mars novels at a bookstore and found that, at the ripe old age of 40, I simply could not read what I've taken to referring to as "stultifyingly thick" prose.
I liked the first movie, but couldn't get through the second and probably will never watch the third one.