On rereading

A first reading tells you what a book is about. A second reading tells you what you missed, which is usually the same thing, only slower.

I have been rereading books I first read in my twenties. The strange part is not that they have changed. It is that I have changed in ways the books seem to have anticipated. A sentence I skimmed past then is now the hinge of the whole chapter. A character I found tedious is now the only one telling the truth.

There is no algorithm for this. You cannot know in advance which books will grow with you. You can only keep a few of them close, and return.