You only ever get to feel certain about the future once it’s already turned into the past.

Likewise, and despite everything I’ve been saying, nobody ever really gets four thousand weeks in which to live – not only because you might end up with fewer than that, but because in reality you never even get a single week, in the sense of being able to guarantee that it will arrive, or that you’ll be in a position to use it precisely as you wish. Instead, you just find yourself in each moment as it comes, already thrown into this time and place, with all the limitations that entails, and unable to feel certain about what might happen next. Reflect on this a little, and Heidegger’s idea that we are time – that there’s no meaningful way to think of a person’s existence except as a sequence of moments of time – begins to make more sense. And it has real psychological consequences, because the assumption that time is something we can possess or control is the unspoken premise of almost all our thinking about the future, our planning and goal-setting and worrying. So it’s a constant source of anxiety and agitation, because our expectations are forever running up against the stubborn reality that time isn’t in our possession and can’t be brought under our control.

My point, to be clear, isn’t that it’s a bad idea to make plans, or save money for retirement, or remember to vote, so as to increase the chances that the future will turn out the way you’d like. Our efforts to influence the future aren’t the problem. The problem – the source of all the anxiety – is the need that we feel, from our vantage point here in the present moment, to be able to know that those efforts will prove successful. It’s fine, of course, to strongly prefer that your partner never leave you, and to treat his or her in ways that make that happy outcome more likely. But it’s a recipe for a life of unending stress to insist that you must be able to feel certain, now, that this is how your relationship is definitely going to unfold in the future. So a surprisingly effective antidote to anxiety can be to simply realise that this demand for reassurance from the future is one that will definitely never be satisfied – no matter how much you plan or fret, or how much extra time you leave to get to the airport. You can’t know that things will turn out all right. The struggle for certainty is an intrinsically hopeless one – which means you have permission to stop engaging in it. The future just isn’t the sort of thing you get to order around like that, as the French mathematician and philosopher Blaise Pascal understood: “So imprudent are we,” he wrote, “that we wander in the times which are not ours… We try to [give the present the support of] the future, and think of arranging matters which are not in our power, for a time which we have no certainty of reaching.”

Our anxiety about the uncontrollability of the future begins to seem rather more absurd, and perhaps therefore a little easier to let go of, when considered in the context of the past. We go through our days fretting because we can’t control what the future holds; and yet most of us would probably concede that we got to wherever we are in our lives without exerting much control over it at all. Whatever you value most about your life can always be traced back to some jumble of chance occurrences you couldn’t possibly have planned for, and that you certainly can’t alter retrospectively now. You might never have been invited to the party where you met your future spouse. Your parents might never have moved to the neighborhood near the school with the inspiring teacher who perceived your undeveloped talents and helped you shine. And so on – and if you peer back even further in time, to before your own birth, it’s an even more dizzying matter of coincidence piled upon coincidence. In her autobiography All Said and Done, Simone de Beauvoir marvels at the mind-boggling number of things, all utterly beyond her control, that had to happen in order to make her her:

If I go to sleep after lunch in the room where I work, sometimes I wake up with a feeling of childish amazement – why am i myself? What astonishes me, just as it astonishes a child when he becomes aware of his own identity, is the fact of finding myself here and at this moment deep in this life and not in any other. What stroke of change has brought this about? The penetration of that particular ovum by that particular spermatozoon, with its implications of the meeting of my parents and before that of their birth and the birth of all their forebears, had not one chance in hundreds of millions of coming about. And it is chance, a chance quite unpredictable in the present state of science, that cause me to be born a woman. From that point on, it seems to me that a thousand different futures might have stemmed from every single movement of my past…