There are many who would argue that there is no time to waste re-reading the same things. That there are too many good books out there to re-read. I agree, there are great books; however, some books are so great they warrant second or fifteenth reads.
We do not read books as they are, we read them as we are.
As we change perspectives or circumstances or age, the way we interact with literature changes. Think about it, did you read To Kill a Mockingbird in 9th grade and hate it only to re-read it as an adult and consider it one of the most profound works you've ever read? Has one verse in the Bible meant something different to you during different seasons of life?
There's a reason for that.
Cognitive functions change. Circumstances change. Times change. You change. The book stayed the same but you change and that changes everything about the book.
As a teenager, I read Pride and Prejudice as a love story. When I got older I read it as a profound explanation on the bonds of sisterhood. I've read it as a comedy, and as a tragedy. I've read it as social commentary and as an exquisite example of language use. I've read this book at least 15 different ways and each time was affected differently. I re-read this book (and a few others) because I am not the same when I start--or end them.
There are great books out there but if one book just sticks with you, do not feel ashamed to re-read it one, two, or thirty-two times. Truly amazing literature works deserve rich exploration.
While others might you think you are wasting time re-reading a book, the truth is, you are reading the same book differently--which is the same thing as reading a new book.
This is why I'm a re-reader.
What are you reading?