Vladimir Nabokov says the best readers are re-readers.
One cannot read a book: one can only reread it. A good reader, a major reader, an active and creative reader is a rereader. And I shall tell you why. When we read a book for the first time the very process of laboriously moving our eyes from left to right, line after line, page after page, this complicated physical work upon the book, the very process of learning in terms of space and time what the book is about, this stands between us and artistic appreciation. When we look at a painting we do not have to move our eyes in a special way even if, as in a book, the picture contains elements of depth and development. The element of time does not really enter in a first contact with a painting. In reading a book, we must have time to acquaint ourselves with it. We have no physical organ (as we have the eye in regard to a painting) that takes in the whole picture and then can enjoy its details. But at a second, or third, or fourth reading we do, in a sense, behave towards a book as we do towards a painting.