“And then one day you find, ten years have got behind you.” – Pink Floyd, Time
Psychological Time Dilation
As we get older, our minds play a mean trick on us: the more we appreciate the value of time, the more fleeting it seems to become. As children, some periods might have seemed like eternities. But as adults, they can seem like mere moments. This effect—where time appears to truncate with age—has a few explanations, with the most popular treating it as a matter of simple math.
As adults, a given stretch of time takes up a smaller fraction of life than it used to. For instance, a year is just 2% of a 50-year-old’s life, but for a 10-year-old, it’s a full 10%. Therefore, the explanation goes, it’s not surprising that time feels longer for the 10-year-old—about five times longer, to be precise.
This explanation is complemented by a second, more psychological, observation. Adulthood often involves more routine, and fewer new experiences compared to childhood. Consequently, adults form relatively fewer novel, vivid memories. This sparser collection of memories can give the impression that, for adults, time contains fewer events, and thus passes more quickly.
This understanding is common not just amongst the public, but also in academia. In Scientific American, brain researchers write, “…our retrospective judgment of time is based on how many new memories we create over a certain period. In other words, the more new memories we build on a weekend getaway, the longer that trip will seem in hindsight.”
Such explanations shed some insight on the matter, which I call psychological time dilation. In particular, they show how the acceleration of time is influenced by hindsight. It’s our memories—not necessarily immediate experience—that make time seem condensed.
On Second Thought
However, this can’t be the full picture. For starters, adults don’t actually accumulate years, as the mathematical explanation (where time feels shorter because it represents a smaller percentage of our life) seems to require. We don’t contain more time than children, because time is not a quantity that can be stored.[1] Nor do we exist across more time than children, because experience—which is all that we truly are—only ever happens now.
Sure, a year comprises less of one’s life than it used to, but nobody canvasses time from the perspective of an entire lifespan. We all, regardless of age, view reality from the present moment, which contains neither time nor lifespans.
The mathematical explanation implies that we can somehow stand outside of the present moment, like atemporal gods able to hold lifetimes in the palm of our hand. But when we think of the past, we are, like our childhood selves, thinking of it from the perspective of the present. And this vantage point is limited, plagued by the usual distortions, displacements, and deletions of human memory.
Given our flawed, incomplete perspectives, it is psychologically dubious to attribute the seeming acceleration of time solely to the mathematics of aging.
But what about the fact that, over a given period, adults form fewer memories? Could this explain things?
No, because this suggests that our perception of time’s passage relies on flipping through a sequence of memories. For instance, if I have three vivid memories from a workweek and eight from a weekend, this logic would suggest the weekend feels longer only after revisiting more than three memories. But the sensation of time flying by often stems from a single, impactful memory. It’s only later that related memories fill in the surrounding context.
Psychological time dilation is less about the perceived length of an event, and more about the time since it occurred. For example, reflecting on my 2011 Eurotrip, it’s not the duration of the trip that startles me; rather, it’s the realization that it was already so many years ago. This recognition occurs the moment the memory surfaces, without needing any additional context.
Aging Memories: A New Explanation
Having reviewed these faults, I’d like to propose a new explanation:
- As we age, we gain more memories.
- With more memories to choose from, we inevitably revisit the same ones less frequently.
- Because we revisit them less often, more time passes between the repeated recollection of any given memory.
- The more time that passes between repeat recollections, the fewer opportunities we have to recalibrate our sense of the time since an event took place.
- Thus, as we age, we’re more often surprised by the passage of time.
Let’s understand with an example.
If a child has only been to one concert, they probably think of it regularly. At first, they might think of it every few minutes, then every few hours, then every few days. Because the child regularly returns to this memory, they are not shocked by how long it has been since the concert took place. Each time they think of it, they can adjust their assessment of the intervening time.
Over time, the child thinks of the concert less: perhaps every few weeks, or only every few months. As they grow older, and attend more concerts, this first concert stands out less and less. Eventually, they might think of it only every few years, or every few decades. At this point, they have ample opportunity for surprise. The last time they thought of the concert, it might have been just a few months ago (and prior to that, just a few weeks ago). But then, as if suddenly, it’s been several years!
Something similar happens when friends grow out their hair. If I see them often, I don’t notice it grow. Because I regularly update my mental image of them, I’m not jolted when, over time, their hair grows long. This mirrors the child who repeatedly recalls the concert, so is not rattled that days or weeks have already passed. Compare this to a friend I rarely see. Upon seeing them after a few months, it might seem like their hair grew all of a sudden, simply because I hadn’t updated my memory of them. This resembles the adult who hasn’t thought of the concert in years, so was used to the memory in which it was just a short while ago.
Some readers might wonder why, upon being jarred by the passage of time, don’t we simply adjust our internal timelines to match reality. Why does the dissonance linger, even if we know better?
The reason lies in how novelty and repetition carve lasting impressions in our psyche. Early, frequent recollections are more impactful than later, less frequent ones. As they say, “Old habits die hard,” “First impressions last a lifetime,” and “As the twig is bent, so is the tree inclined.” Thus, when we revisit newly formed memories, we’re not just recalling them; we’re imprinting the perception that these events occurred not so long ago. For instance, in the days, weeks, and months following our first concert, we imprint the memory with a feeling of recentness. When we recall the concert years later, that initial imprint influences our perception, which makes it feel like the memory shouldn’t be so dated.
In other words, we become habituated to memories which point to a much closer past. And this habit dies hard.
Time Slips Away?
When memories feel like they should point to a recent time, it can be disconcerting when they don’t. This can leave us feeling as though life has passed us by. Recognizing this sensation as an artifact of memory, rather than a true loss of time, helps dispel our angst. After all, it is only by weaving a rich tapestry of memories that we gain a deeper appreciation for life’s fleeting moments.
[1]If you disagree, ask yourself how you access the past and the future. You’ll find that they are only accessible as fleeting thoughts in the present. And these thoughts do not contain the past or future, just as the thought of a car does not contain the car.
Stories From the Ground. 
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