Do you take time to re-read a book that you have read before? Is there a time frame for going back to read a book that you've read in the past or you just don't bother with reading it again?
Generally speaking, I do not re-read books, even the ones that I thoroughly enjoyed. However, I re-read books when I am working on an article/review about the book or want to present a paper on the book. I sometimes read random pages of books, especially when I am searching my book collection.