The Trilogy was big when I was in college, and that's when I read it. The "authorized" paperback edition, with a note by Tolkein that said "those who approve of courtesy (at least) to living authors will purchase it and no other."

A reviewer on a popular movie review website declared that he had not read any Harry Potter books, and wouldn't until after he'd seen the movie.

I'm not sure how well that order of things works out. There's no real way to tell if that's your problem or not.

It's hard to think of any example where I saw a movie I liked and then read the book for the first time. "Iron Giant" was one, and to my surprise, the movie was very different and considerably better.

I took a lot of trouble when my kids were young to expose them to the original books of Dr. Doolittle, Mary Poppins, Bambi, and many others, so they wouldn't grow up thinking of Rex Harrison and Julie Andrews first.