I’m proud of how mild-mannered my midlife crisis is. While the cliche involves the purchase of a Porsche or a frantic fling with a colleague, I’ve mainly fallen back into the geeky preoccupations of my youth, such as founding poetry clubs and playing niche racket sports. Nevertheless, on the cusp of turning 50, and having just been beaten by my 11-year-old at Scrabble, I’m thrilled to have found a book that addresses my small struggle: an elegant discourse on the deep wisdom that I’m hoping will characterise my remaining years. First, the author, a clinical psychologist named Frank Tallis, diagnoses...