Scott Sumner’s recent Substack on subjective time certainly caught my attention and warrants a response, if only to organize my own thinking on the subject. Though its worth the quick read of the full article, his thesis is, roughly speaking: as we age, each year represents a smaller fraction of our total experience, so time accelerates. Subjective time = 1/age. By this formula, a decade at 100 feels like a year at 10. His consoling conclusion? We shouldn’t fret about mortality—by seventy, we’ve already lived most of what makes life meaningful.

It’s elegant. It resonates. It’s… not a very defensible position.

Sumner’s formula treats human experience like a savings account where childhood deposits compound forever. But this ignores how memory actually works, what makes a life valuable, and—most importantly—how meaning is constituted in time. The math is solid, but the underlying premises are almost willfully ignorant of how human value works.

What follows is both critique and charity. I’ll argue that Sumner’s reasoning fails on multiple levels, but I’ll also grant that he’s pointing toward something real about aging that deserves serious attention.

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The Linearity Problem

Sumner’s formula assumes all lived time accumulates as equally accessible experience. But infantile amnesia extends to age three or four, with only fragmentary memories before age seven. Those early years, which Sumner counts as experientially “longer”, are largely cognitively inaccessible to adult consciousness.

There’s something absurd about treating a two-year-old’s experience as a substantial deposit in the existential savings account when that experience won’t survive as autobiographical memory. You can’t withdraw what was never really stored. Even later childhood memories are subject to intense distortion over time as we constantly reconstitute the memories under the narrative of our lives (more on this configurability later).

Moreover, memory retention in older adults doesn’t follow his inverse age curve. A seventy-year-old often remembers last Tuesday’s mundane lunch better than some supposedly formative childhood experience. Recent events, even routine ones, can be deeply contextualized in rich networks of meaning that a child simply cannot access.

Sumner conflates raw lived time with retained, meaningful experience. Bergson made the crucial distinction: durée (lived duration) versus temps (spatialized clock time). Sumner treats duration (and, by extension, meaningfulness) as if it were measurable and additive, but lived time is qualitative, heterogeneous, and its significance is lumpy. You can’t sum it one increment at a time like days on a calendar.

As Bergson put it in Time and Free Will, which I have now spared you all from reading: “[Duration is] the form which the succession of our conscious states assumes when our ego lets itself live, when it refrains from separating its present state from its former states.” This duration of meaningfulness is separate from chronological time and unevenly distributed. Sumner is doing exactly what Bergson warns against—cutting duration into discrete, comparable units.

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The Novelty Problem

Sumner seems to be overvaluing novelty, as such, while also overstating naivete’s value in generating novel experience. While it’s true the pleasure of a glass of wine may be dulled sip by sip, one’s pleasure in the act of drinking a glass of wine can be greatly enhanced by sharing the rest of the bottle with cherished friends with whom one shares a history. Sumner ignores the way in which experience creates the possibility for a new class of novelties, which are predicated on the gains from prior experience and therefore inaccessible to the novice.

What’s more, back to Bergson’s distinction above, it is precisely routine and continuity that enables duration and helps us tie our cognitive past to our lived present, as well as our imagined future. The constant and repetitive parts of our lives are not mundane fat to be trimmed; they are part of the very fabric of what we understand to be our “self” over time. They are the setting for the story of our lives, and it is the persistence of various givens that create and evolve the backdrop against which our character can be seen.

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The Discount Rate Problem

Sumner is an economist, so let’s meet him in his own field and talk about discount rates. In economic theory, we discount future utility because of uncertainty, time preference, and diminishing marginal returns. Sumner does something strange: he applies a negative discount rate to childhood experiences. An experience at age eight supposedly carries more weight than an equally vivid experience at forty, precisely because it happened earlier.

This is irrational. Those early experiences have much higher uncertainty of retention—we don’t know which will be remembered or how they’ll integrate into our adult consciousness. And if we’re talking in terms of revealed preference, adults consistently choose to keep living rather than cash out on their supposed experiential peak from childhood. To be fair, this is also what makes Sumner’s argument novel, but in this case, I have to side with the prevailing intuition.

But there’s a further issue, one that economists are prone to making: human flourishing isn’t a consumption problem. Aristotle understood this when he argued that eudaimonia is an activity (energeia), not a possession. Life’s value emerges from actualization over time, not from front-loaded experiences.

Many virtues that matter most—practical wisdom, deep relationships, moral agency—require time to develop. They can’t be deposited in childhood and withdrawn at seventy. Sumner is treating experiential meaning like a fungible commodity, which completely misses what makes a life valuable. We’re not optimizing a portfolio of sensory impressions, as if we were creating a scrapbook or accruing savings in a bank.

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The Reductio Problem

Imagine that Sumner, at his current age of 70, really follows his own theory. If each remaining year is experientially negligible, basic cost-benefit analysis suggests he should front-load everything toward immediate pleasure. Why read? Why maintain relationships? Each passing day yields diminishing subjective returns.

His theory suggests he should pursue dangerous novelty—anything to break through experiential diminishment. If routine barely registers, rational behavior means high-risk travel, extreme sports, whatever creates surprise.

Or better yet, if childhood experiences are so valuable, shouldn’t he spend all his resources reconstructing those memories (via deep nostalgia, psychedelic experience, psychoanalysis, etc.?) One recovered childhood memory might be worth years of present experience by his formula.

The implications get absurd. Why would anyone past fifty invest in education or start projects? Learning Italian at seventy is irrational—the experiences it enables are subjectively worthless.

Yet we observe the opposite. Many people report their most meaningful experiences in later life, when they have the wisdom to appreciate depth over novelty. Also, as described above, a new set of possibilities for novelty emerge each time we grow and change. These gains accrue most heavily later in life.

Sumner’s own intellectual productivity at seventy contradicts his theory. His argument turns aging into pure loss rather than development, which seems empirically false about how people actually age and how they subjectively experience it.

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An Alternative Model (if we must model)

Imagine meaningfulness distributed along a bell curve centered on the present moment, attenuating in both temporal directions (past and future). Memory fades as we look backward—not just because we forget, but because past experiences lose their grip on current projects. Similarly, our capacity to project realistic futures diminishes the further out we look. What remains is a cluster of meaning centered on recent events and near-term possibilities.

This model captures something phenomenologists recognized about consciousness. Husserl described the triadic structure: retention (just-past), primal impression (now), protention (about-to-be). Both retention and protention fade in intensity as they recede from the living present.

This isn’t just a cognitive phenomenon, it is an emergent property of the way consciousness relates itself to meaningfulness: we are fundamentally storytellers about our own lives, and the meaningfulness of a particular memory or episode always exists in relation to the role it plays in our current understanding of the story. When we say we want our lives to be meaningful, we mean that we want them to be meaningful to us now, from our present perspective.

And that perspective is a moving target. The meaningful temporal horizon isn’t fixed—it constantly reconstitutes itself around present concerns. If this is right, Sumner’s claim that childhood experiences accumulate permanent value makes no sense. A seventy-year-old’s temporal horizon includes recent relationships and near-term projects, not some abstract sum of all past wonder.

Meaning isn’t cumulative—it’s configurational. What matters isn’t total experience but the richness of your current horizon and your capacity to project meaningful possibilities forward. The peak moves with you, and your memories and views are reconfigured to adapt to your present understanding of yourself and the world in which you live.

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Sumner’s Advantage

Sumner is seventy and I’m not, and that matters more for this discussion than in your average debate, given the subject matter. He’s speaking from lived experience that deserves respect, even if his philosophical framework fails.

The most serious insight is that perhaps there really is experiential saturation in aging. After seventy years, the categories through which we apprehend the world become so established that genuine surprise does become harder. That second trip to Italy does feel less revelatory—not just because of the prior memory, but because of something about how consciousness structures itself through accumulated experience.

He also understands something about mortality’s weight that’s hard to grasp externally. When time is limited, that constraint changes how you evaluate past versus future. It seems natural to overrate the past, which seems so abundant, versus the future, which seems so scarce. But even granting that point, I see no reason to prefer to distant past to the near past in that scenario. Sumner should go outside and do something fun today.

Finally, perhaps his consolation isn’t really mathematics—it’s dignity. If aging brings real losses (physical, cognitive, social), then honoring what’s already been lived isn’t philosophical error but psychological wisdom. Even if the logic fails, it might serve an existential function for someone facing mortality, as we all to some extent do at all times.

My compromise would be to say that fighting aging as pure loss might be an error, but recognizing earlier life phases as containing something unrepeatable and sufficient is an absolutely worthy exercise. Perhaps this is where Sumner is coming from, at the deepest level.

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Framework for a Better Theory

First: life’s value isn’t measured by experiential accumulation. The narrative structure matters more than quantity (and even the intensity) of sensations. We constitute identity by weaving experiences into coherent stories. An older adult has vastly richer narrative resources than a child, even if its moments might typically feel less novel. Our sense of self isn’t built from raw intensity but from our capacity to configure experience into meaningful patterns over time.

Second: different goods emerge at different stages. Practical wisdom deepens with experience. Relationships develop texture through shared experience. Understanding enriches through what we might call “long experience”.

Our “self” is not made of discrete, novel occurrences but rather the integration and reinterpretation of those occurrences through expanded horizons. A first kiss at fifteen and a conversation with your partner at fifty are likely incommensurable goods; yet both are valuable, and it’s hard to say which is more valuable at a given moment without present context.

Third, most paradoxically: finitude enables meaning rather than limiting it. Heidegger saw this, and it’s one of his more elegant insights. Our Being-toward-death (Sein-zum-Tode) isn’t limitation but what gives existence its motivating force. Immortality might collapse temporal urgency into indifferent presence. We’d have no reason to care about particular people, projects, moments. In economic terms, there would be no scarcity value.

The constraint creates focus. This is why the bell curve model matters: meaning centers on the present not because the past doesn’t matter, but because we are temporal beings, always projecting forward from where we stand. The moving horizon is a feature, not a bug, saving us from paralyzing nostalgia.

Aging is both decline and development. Yes, there are losses—no one should romanticize that. But there are gains: integration, coherence, and depth to the story of our lives enabled by enduring learning and growth. These gains don’t quantify in Sumner’s formula, but they’re real. And they’re often more valuable than the raw novelty of youth, even if they’re harder to articulate or measure.

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Conclusion

Sumner raises important questions about temporal experience and mortality. His mathematical consolation fails because it treats human lives as optimization problems rather than ongoing meaning-making activities.

But his lived understanding deserves respect. Something real changes in time consciousness as we accumulate decades. The challenge is how to honor that without falling into ledger-book thinking about life.

The better truth: meaning is relational, configurational, and centered on present horizons, which move with us through time. We’re not depleting wonder from a finite reserve, we’re continually reconstituting the meaningful world from where we stand. That happens differently at different ages, with different goods available at different times.

Sumner writes: “Even if you only live 100 years, you haven’t missed all that much in subjective terms.” I’ll offer a different consolation: even at 100, you’re still capable of meaning-making in the present. That’s what matters, and it has nothing to do with fractions.

Hat tip to Tyler Cowen at Marginal Revolution for putting the Sumner piece on my radar.