It’s the most obvious fact in the world – or at least it ought to be – that life is a series of trade-offs. Spend $10 on a cheeseburger, and you can’t also stash that same $10 in your savings account. Marry your college sweetheart, and (for the time being) you can’t marry anyone else. Naturally, it’s the same with your work: any given hour, week or year dedicated to one project can’t be used for another. Yet most of us, whether we realize it or not, are deep in denial: we make enormous efforts to ignore the reality of tradeoffs – and, as a consequence, deny ourselves the best chance of a maximally fulfilling creative career. Unlikely as it sounds, recognizing this truth is a powerful cure for overwhelm, and a way to achieve relentless focus that will last a lifetime.

It’s an understandable error. Faced with multiple job offers, creative possibilities, or just a long to-do list, who wouldn’t seek ways to do them all, rather than having to choose? After all, as the management writer Greg McKeown points out, “by definition, a trade-off involves two things we want. Do you want more pay or more vacation time? Do you want to finish this next email or be on time to your meeting?” The ideal answer would always be yes to both – and a thousand productivity gurus are standing by, ready with techniques to boost your efficiency. Sometimes, that’s helpful. But far too often, that promise of more productivity is just a seductive way to avoid facing up to trade-offs – with the result that you fritter your focus, spending time on everything except the work that matters most.

At the risk of sounding melodramatic, it’s worth noting why trade-offs are a problem in the first place: because you’re going to die. Barring any breakthroughs in the efforts of certain Silicon Valley billionaires to “solve death,” you have an absurdly finite span in which to accomplish a handful of the infinite number of things that you could, in theory, achieve. It might seem like your mortality is irrelevant when it comes to deciding, say, whether to spend the next half-hour on email, or sketching project ideas. But if you had infinite time, there’d be no decision to make. Mortality is the only reason to care about time management at all.

And death, of course, is absolutely terrifying: no wonder we try so desperately hard to believe the modern cultural message that there are no limits, and everything is possible. We suffer, as the novelist and environmentalist Wendell Berry puts it, from “a disease of limitlessness”. And it is a disease: people who ignore the reality of their limits, who always imagine there’ll be time later on, who Berry writes, “never make the most of anything.”

The good news is that facing up to your limitedness – and with it, to the necessity of trade-offs – needn’t be depressing at all. In 1955, in a largely forgotten book entitled Teach Yourself To Live, an upper-crust English lawyer called Charles DuCann likened it to taking a cold shower. “At first it may shock. But in a while it is exhilarating. You know where you are… you are no longer befogged and bewildered by a false and misleading illusion about yourself and life… like most people.” When a friend asks if you’ll jump on board with her new business, or a possible freelance gig arrives by email, you’ll see more clearly what you’re giving up in exchange. Which means that if you do decide to say yes, you’ll be freed from the nagging worry that you ought to be doing something else.

There are many practical ways to make trade-offs feel more vivid. For a start, you could take the advice of the time management coach Mark Forster, and abandon your “catch-all” to-do list in favor of one limited to five entries. (If you can only choose five, you’re forced to make tough decisions – whereas catch-all lists encourage the illusion that you might, somehow, get everything done.) Or follow Warren Buffet’s suggestion: list your 25 top career goals, choose the five you value the most, then treat the remaining 20 as your “avoid at all costs” list. They’re the dangerous ones: the somewhat attractive goals most likely to lure you from your truly important priorities.

Ultimately, though, it’s a matter not of techniques, but a shift in perspective: to learn to see everything you choose to do (including, by the way, choosing to procrastinate on making a decision) as a choice not to do a million other things. You can’t fit everything in – and any productivity expert who suggests otherwise is like the “friend” who urges a recovering alcoholic to relax with a gin and tonic. Sober up! Time is short – and the big surprise is that life and work are both far more thrillingly meaningful once you realize it.