Every hour spent at our desk is one fewer with friends. Every joule of energy expended in pursuit of a dream is one fewer for family.

Nevertheless, you might argue, a glimmer of satisfaction is still a glimmer. Realising our ambitions still makes us happy, even if we’re liable to overestimate the exact amount. Therefore, you might claim, our wonky affective forecasting gives us no reason to renounce our ambitions. But to think this way is to overlook ambition’s costs. We must recognise that our ambitions are not benefactors who give without taking. We pay for our ambitions with our time, our energy, and our emotional investment, and we draw on limited funds to do so.Nights that could have been restful are dogged by tossing and turning. Days that could have been tranquil are blighted by self-censure and restlessness. At its extreme, ambition compels us to give all that we have. Crusoe’s ambition drove him from Hull to Great Yarmouth, on to London, then to Guinea on the west coast of Africa, over to Brazil, and to a shipwreck on a remote island. By the time he returned home over three decades later, his father was dead. We should beware the tempting thought that our own ambitions are not so costly. Nowadays we pay in smaller instalments, but the final price may be greater still.