"Think of books as the collective advice we have from previous generations. It has the advantage of not being forgotten. We filter the books through the collective process of recommendation. Books that fall out of circulation tend not to be as useful. Advice ought to follow a similar rule. The longer I delay taking recommendations, the more rigorous the test. If my wife can still remember and be bothered to recommend something a year later, it’s probably a good call. She’s less likely to persist with the stuff that isn’t so good."