Go back to the books you read years ago. The ones you still think about after all these years. The ones you learned a lot from. The ones that helped, inspired or changed you.
What will happen? A new discoveries will happen.
You see, the things you learn from a book aren’t only what author put there. What you get from a book, is a mix of author’s intention and… you. What are your values at the time of reading? What is your knowledge level of the topic? What are your needs and expectations? What is your view of the world?
Are Tolkien’s books still adventure books that cause thrills of excitement? How do you look now at Sam’s devotion? What do you feel about Boromir’s actions? Who is Frodo now, after you also read “The Hero with a Thousand Faces”? What does it say about you and your journeys?
Same with professional books. Read “The Pragmatic Programmer” again (or whatever book is The Book in your field of expertise). You think you won’t learn anything new? Ha! I bet you will.
Give it a try. Go back in time. Read again. The books are the same. But you changed, and that might be an interesting discovery.