Time is the one thing everyone gets in the same currency. Nobody’s hour is longer than anyone else’s. And yet most of us treat it as if the supply were endless, spending it the way we’d never spend money we actually cared about.I think that gap, between how precious time is and how casually we hand it away, is what Seneca was pointing at nearly two thousand years ago.

The line opens his first letter to a friend named Lucilius. Seneca wrote that “Nothing, Lucilius, is ours, except time. We were entrusted by nature with the ownership of this single thing, so fleeting and slippery that anyone who will can oust us from possession.”

I read that as a claim, not a fact. A life is obviously made of more than time. But as a way of reframing what’s yours, it holds up.

What Seneca meant

His point in that first letter, titled ‘On Saving Time,’ is narrow and sharp. Property can be taken and returned. Reputation comes and goes. Time, once spent, is simply gone, and other people are always reaching for it.

What struck me on rereading it is how little of the loss he blames on bad luck. Most of it, he says, we give away ourselves. He called the worst kind “the most disgraceful kind of loss”, the loss due to carelessness.

He goes further, and the picture is bleak. Seneca claimed that “the largest portion of our life passes while we are doing ill, a goodly share while we are doing nothing, and the whole while we are doing that which is not to the purpose.”

He’s exaggerating to make the reader flinch, I guess. But the three things he names, doing harm, doing nothing, and doing things beside the point, are recognizable enough that the exaggeration lands.

His most famous version of the argument comes from On the Shortness of Life. There, in C.D.N. Costa’s Penguin translation, he insisted that “It is not that we have a short time to live, but that we waste a lot of it. Life is long enough, and a sufficiently generous amount has been given to us for the highest achievements if it were all well invested.”

Whether life is in fact long enough is his opinion, not something I’d assert. The useful part is the reframe: the problem isn’t the amount, it’s the spending.

The same patterns, in modern clothes

What makes the line stick is that the behavior he described hasn’t changed. If anything, we’ve scaled it up. In the same Costa translation, Seneca observed that “People are frugal in guarding their personal property; but as soon as it comes to squandering time they are most wasteful of the one thing in which it is right to be stingy.” That describes a lot of how people behave.

The numbers fit almost too neatly. In 2024, Americans age 15 and older averaged 5.1 hours a day of leisure and sports, with TV alone accounting for 2.6 hours of that, more than half. Worldwide, the typical internet user now spends 6 hours and 40 minutes a day online across all their devices.

None of that is automatically wasted. Rest matters. But almost none of it is likely chosen with the care Seneca thought time deserved.

Attention is starker still. Gloria Mark, a professor who has tracked screen behavior for two decades, found that the average time people stay focused on a single screen has dropped from about two-and-a-half minutes in 2004 to roughly 47 seconds now. And getting back on track after an interruption can take about 25 minutes. Seneca’s “doing that which is not to the purpose” now happens in 47-second bursts, all day.

What owning your time might look like

The temptation is probably to read all this as a case for productivity hacks.

However, Seneca wasn’t handing Lucilius a system for getting more done. He was pointing at attention and intention, at noticing where the hours go rather than squeezing more out of the leftovers.

Mark, who studies the same problem with data Seneca never had, lands somewhere close to him. Her advice is plain: she says, “We have limited and very precious attentional resources — use them wisely.” Swap “attentional resources” for “time” and you’ve more or less got the opening of Letter I. A Roman writing late in his life and a modern researcher watching people flip between browser tabs arrive at nearly the same instruction.

That’s either reassuring or depressing, depending on how you look at it.

In practice, I think it means something smaller than a life overhaul: the pause before you agree to the thing you don’t want to do, or catching yourself mid-scroll and asking whether this is chosen or just fallen into. It isn’t self-denial, just noticing when the hours are leaving, and whether you’d have signed off on where they went.