“Keep it inside you, where it belongs” could also be said of vanity-blogs, LOL. And yes, I know that’s what I write. Get over it. This is fun and therapeutic whereas Joseph Epstein makes writing a book sound awful.
Beyond the obvious motivation for wanting to write a book — hoping to win fame or fortune — my guess is that many people who feel they have a book in them doubtless see writing it as a way of establishing their own significance. There lurks, perhaps, in every human heart, wrote Samuel Johnson, a desire of distinction, which inclines every man to hope, and then to believe, that nature has given himself something peculiar to himself. What better way to put that distinction on display than in a book?