If we see someone throwing money away, we call that person crazy. This bothers us, in part, because money has value. Wasting it seems nuts. And yet we see others—and ourselves—throw away something far more valuable every day: Time.

Unlike the predictable reaction we have to someone throwing away money (they’re crazy), we often fail to think of the person who wastes time as crazy. And yet time is a truly finite, expendable resource: The amount we get is uncertain but surely limited. It’s even more insane to waste than money — we can’t make any more when it runs out!

The Roman philosopher Seneca said it well in a letter to Paulinus:

It is not that we have a short space of time, but that we waste much of it. Life is long enough, and it has been given in sufficiently generous measure to allow the accomplishment of the very greatest things if the whole of it is well invested. But when it is squandered in luxury and carelessness, when it is devoted to no good end, forced at last by the ultimate necessity we perceive that it has passed away before we were aware that it was passing.So it is—the life we receive is not short, but we make it so, nor do we have any lack of it, but are wasteful of it.

[…]

I cannot doubt the truth of that utterance which the greatest of poets delivered with all the seeming of an oracle: “The part of life we really live is small.” For all the rest of existence is not life, but merely time. Vices beset us and surround us on every side, and they do not permit us to rise anew and lift up our eyes for the discernment of truth, but they keep us down when once they have overwhelmed us and we are chained to lust. Their victims are never allowed to return to their true selves; if ever they chance to find some release, like the waters of the deep sea which continue to heave even after the storm is past, they are tossed about and no rest from their lusts abides.

The best way to spend money is to buy time. In life and business, the people we admire are often the ones who have firm control over their time. Rarely are they wasting a moment, and if they find themselves wasting it, they adjust quickly.

Time is one of the most under-appreciated models that we all encounter, and yet it’s the most ubiquitous. When employed correctly, time becomes an amplifier. When spent without consideration, it becomes a persistent source of regret.

Four Ways We Misunderstand Time

1. Productivity: We actually don’t want to be more productive. What we really want is more time. And yet because we don’t properly value time, we never end up with more; even when we find ways to work more efficiently, we don’t actually use it wisely. We simply layer in more work.

2. Investing in Learning: The upfront costs are real and visible and, like any investment, the future payoff is uncertain. So we tend to skim the surface, thinking this will “save us time” versus doing the real work. Yet this surface-based approach leads to no improvement in our ability to make decisions. In fact, it may harm us if we think we’ve learned something for real. Thus, surface learning is a true waste of time. It’s just that the link to our bad learning is unclear, so we rarely identify the root cause.

3. Relationships: We’re often too “busy” to spend time with the ones we care about. The very parent at the park playing on his iPhone while his children run around playing and laughing is the same one, who, when you fast-forward the axis of time, wants those precious moments back. Likewise, the “busy” 30-something who can’t make time to see their parents wishes to have them back after they’re gone. They wish for more time with them.

4. Meetings: Meetings are part of how many of us earn a living. Often, however, they’re poorly organized and poorly run. Lacking an agenda or decision, they become nothing more than half-meeting half-gossip session. A giant waste of time.

Time is invisible, so it’s easy to spend. It’s only near the end of our life that most of us will realize the value of time. Make sure you’re not too busy to pay attention to life.