An interesting quote on re-reading books:
"The sure mark of an unliterary man is that he considers ‘I’ve read it already’ to be a conclusive argument against reading a work.
We have all known [people] who remembered a novel so dimly that they had to stand for half an hour in the library skimming through it before they were certain they had once read it.
But the moment they became certain, they rejected it immediately. It was for them dead, like a burnt-out match, an old railway ticket, or yesterday’s newspaper; they had already used it.
Those who read great works, on the other hand, will read the same work ten, twenty or thirty times during the course of their life."
--C.S.Lewis, An Experiment in Criticism