Schwandt proposed a mathematical model in which experienced life-satisfaction is a function of how well life is going at the time, combined with optimism for the future and disappointment about the present.

Mill’s insight in this passage has a name: the paradox of egoism. And it has a history, dating back at least to sermons preached by Joseph Butler at the Rolls Chapel in London, which were published as a book in 1726.9

Think of Count Vronsky, seducing Anna Karenina: “He soon felt that the realization of his longing gave him only one grain of the mountain of bliss he had anticipated. That realization showed him the eternal error men make by imagining that happiness consists in the gratification of their wishes.”13

How should we think about the lost opportunities, the regrets and failures, the finitude of life and the rush of activities that drive us through it?

So tell yourself this: although I may regret regret, desire that no desire go unfulfilled, I cannot in the end prefer to have desires that could be fully met. The sense of loss is real; but it is something to concede, not wish away. Embrace your losses as fair payment for the surplus of being alive.

You need the mastery of mental focus, of your own thoughts and feelings, that is nurtured by mindfulness meditation.

Elliott Jaques had linked the midlife crisis with transformation and creative rebirth.

Other activities are “atelic”: they do not aim at a point of termination or exhaustion, a final state in which they have been achieved.

make friends for the sake of saying goodbye.