There are more books than any of us will read in a lifetime, which can make re-reading feel like a waste. Why spend a week on something you already know, when there is so much you do not?

Because you do not know it, not really. The first time through a good book, you are following the story. The second time, freed from wondering what happens, you notice how it happens: a phrase that foreshadows the ending, a minor character who mattered all along.

And you are not the same reader. A novel read at twenty and again at forty is two different books, because the reader brings different things to it. Re-reading becomes a way of measuring how you have changed.

So keep a short shelf of books you return to. Let the to-read pile wait a week.