Optimisation is a genuinely powerful way of thinking, and within its proper territory, I would not dream of talking anyone out of it. The trouble begins when we extend it, quietly and without ever quite deciding to, from the parts of life that have settled goals to the whole of a life, whose goal is exactly the thing in question. You cannot optimise a journey before you have worked out where you are going, and the peculiar ache of the thin life is that it has mistaken motion for direction.