Sooner or later, it’s expected that every responsible young adult will eventually find their way in life. It often boils down to two immediate options: get a job, or study.

One of these decisions, whether I know it or not, is going to set the tone for the rest of my life. I may take up a job that I will work for the next ten, twenty, thirty plus years. I may choose a degree and end up in a certain career that will define my existence.

And yet it won’t. There’s nothing to say that a career choice need necessarily define a life. Though people of the same career may have certain traits in common with one another by necessity, they are by no means all cut the same.

In my experience, possibly the greatest tragedy in life the realisation that we will never experience everything there is to experience. There are opportunities we have long missed that we will never be able to revisit. We have one life, and there is no return to the past.

It’s a sign of poor mental health to be overly-focused on the past, to be constantly wondering, to be regretting, to be fearing. I’ve struggled for most of my life to lose the baggage that I’ve brought with me from whatever I’ve done in the past, mistakes both great and small.

And yet these are somehow more salient than all the good I’ve done. Somehow, I’ve often found it easier to focus on the things that have gone wrong, rather than the things that have gone right.

And yet, the past is unchangeable, unmovable. No force of will may ever change it, and all efforts to do so are an exercise in futility.

What’s more, forgetting the past is just as dangerous. If we forget the lessons we have learnt, we are doomed to repeat our failures. They say that insanity is doing the same thing over and over again and expecting different results.

As dangerous as regretting or forgetting the past is fearing the future. For too long we could fear what may come – that we may have to move and leave our family, for example. That our dog may die. That our partner may leave us, or die. That we may die.

Death is amongst one of the greatest human fears, but it is an inevitability. Avoiding death is as much of a futility as trying to change the past. Imagine how much more we could achieve if we directed the energy we spend on either of these things were instead directed towards bettering the future?

Lucius Annaeus Seneca, one of the great Stoic philosophers, once wrote: “It is not that we have so little time but that we lose so much. … The life we receive is not short but we make it so; we are not ill provided but use what we have wastefully.”

Seneca was not a young man at the time of writing, and the friend he wrote to was likewise in the later years of his life. And yet, he felt that life was long enough, that life was enough time. That, provided it was used carefully, we could make the best of it.

Yes, we cannot do everything there is to do in life, but perhaps we would not want to. I might wonder what skydiving is like, for instance, but my fear of heights makes me hesitant to try it. The time (and money) that I could spend on that could instead be used for things that are more likely to make a bigger difference to my life.

And perhaps attempting to do everything life is a misunderstanding of the point of life – not to achieve everything there is to achieve, but to live the best life you can. We lost that if we obsess over the past or fear the future. Living in the present, and doing the best you can today is the only way to live without futility.

For me to make a past I’m happy with, I need to start with today. To reach death and not be sad to go, I need to also start with today. Wise use of the present is the only way to fight futility.