When I was in college i took a Modern Science Fiction literature class. It was meant as an elective for those majoring in English, but the teacher was inspired by how much I had read, etc. We had something like 18 books to read during that course and I had already read thirteen of them. I read three and chose not to read Dune because I had seen the movie. Well, he knew many students over the years would pull that stunt and so he asked a question on the final about Salusa Secundus. Well, this is in the book, but not the movie. I laughed when i went to pick up my final after the end of the semester and he laughed back when I admitted to not haven read the book. I then spent the summer reading it and the many that followed it. I think I stopped after five books. It was bad enough the Foundation Trilogy was something like 13 books I didn't need to go down another worm hole (pun intended).