The title of this post is the title of one of the chapters (one of the attempts at an answer), which explores Montaigne's reading, and his claims to extreme forgetfulness and slow wits. It is consoling to think that reading a lot, forgetting most of it and being slow-witted might add up to a good way of living. Maybe, as my memory becomes ever more sieve-like and my wits ever slower, I am making a virtue out of necessity here - or is there something in it? Do forgetfulness and slow wits (and, of course, extensive reading) save us from worse things? Probably they do.
Sadly, it does not appear to have been published in the US. The best secondary book I have read on Montaigne's genius is Jean Starobinski's Montaigne In Motion. Montaigne - apart from the Gospels - is the biggest influence on my own extended essay on friendship, "If Love Were All," the third part of "Love Undetectable", and central to the definition of conservatism I offer in "The Conservative Soul".
Reading him changed my life.