From Darwin’s worms to Turner’s sunsets, why wonder may be the last great art of growing old.

By Michael Cummins, Editor, September 4, 2025

The rehearsal for memory begins with a question. Where on earth do trees grow with square trunks? It sounds like a riddle from a child’s notebook or a surrealist painting. And it is the question that opened a recent episode of The Guardian’s Science Weekly podcast. The scientists on the program did not answer right away. They made us wait. And that pause, that stretch of uncertainty, is the secret heart of curiosity—the ache that sharpens the mind. To age well, perhaps, is not to gather the answers, but to continue cultivating that ache.

Consider the way a child treats the world. A blurred photograph, a half-said phrase, a dinosaur’s unpronounceable name—all of these are invitations to wonder. Researchers like Dr. Matthias Gruber and Dr. Mary Watley have made a career out of studying that impulse, and what they’ve found is both simple and astonishing. Curiosity—when we let it run its course—lights up the reward circuits of the brain. The hippocampus stirs awake. Memory forms like clay pressed to the mold of desire. The moment of anticipation, the leaning forward in one’s chair before the answer drops—that is where learning becomes not a duty but a joy.

It sounds obvious in theory, yet how often do we short-circuit it? A conversation stalls on a forgotten film title and within seconds a phone flashes the answer. We no longer linger in the sweet spot where knowledge is almost, but not quite, in reach. We save ourselves from the discomfort of not knowing, and in the process, we cheat ourselves of the neurological reward. As Jordan Litman writes in The Curiosity Effect, “we rob ourselves of the very thing that makes knowledge memorable when we outsource every answer to a device.” One study found that people would rather sit with a question, guessing and fumbling, than have the answer immediately revealed. The waiting was the pleasure. In a culture allergic to delay, what are we losing by satisfying every flicker of curiosity instantly?

The story deepens when curiosity is followed across a lifespan. As children, we are indiscriminate: we want to touch, taste, and know everything. By the time we hit our forties, something constricts. The world presses in—mortgages, children, aging parents, bosses, and deadlines—and curiosity, broad and restless, shrinks to a pinhole. This is the curious paradox: we are at our least curious precisely when we are most in need of escape. In middle age, to wonder feels like a luxury. Yet in the later decades, curiosity resurges, not in breadth but in depth. Watley and colleagues, in their 2025 study Curiosity Across the Adult Lifespan, found that while trait curiosity—the stable appetite for knowledge—declines with age, state curiosity, or situational bursts of interest, actually increases in older adults. “We are not less curious with age,” they write, “but differently curious.”

The arc of curiosity across life resembles a river: wide at the source, narrowed by the rocks of midlife, widening again as it approaches the sea. Sakaki, Yagi, and Murayama argue in Curiosity in Old Age: A Possible Key to Achieving Adaptive Aging that this narrowing and widening reflects the brain’s flexibility itself: “Curiosity serves as a dynamic coping resource, allowing older adults to adapt cognitively and emotionally to the challenges of aging.” To age with curiosity is not simply to preserve information, but to practice resilience.

Wallace Stevens sensed this:

Death is the mother of beauty. Only the perishable can be beautiful…

Aging, in his vision, is not decline but the condition of wonder itself. We perceive beauty because we know it vanishes. Curiosity, then, is a metaphysical defiance, a way of leaning into what slips away. Wallace Stevens also reminds us:

Reality is a cliché from which we escape by metaphor.

For the aging mind, curiosity is the metaphorical escape hatch, a refusal to let life calcify into cliché.

Why does it matter? Because curiosity, more than any supplement or crossword puzzle, appears to be a quiet ally against cognitive decline. Those who sustain trait curiosity—the broad hunger for new things—show stronger “cognitive reserve,” the brain’s ability to withstand the slow bruises of age. As Gene Cohen put it in The Aging Brain, “curiosity is not a byproduct of youth; it is a neuroprotective force, a way the brain rehearses its own adaptability.” Cohen’s case studies tell of octogenarians who take up painting, learn Mandarin, or dive into family genealogy not for professional gain, but for sheer, stubborn delight. Their curiosity does not erase aging; it rewrites its script.

Charles Darwin understood this in his final decades. Long after the voyage of the Beagle and the storm of On the Origin of Species, he retreated to Down House, weakened by chronic illness yet still possessed by restlessness. His notebooks from his seventies reveal obsessions not with grand evolutionary arcs but with the behavior of earthworms, how they swallowed soil, turned fields, altered the landscape. Many mocked these studies as trivial. Darwin did not. To him, worms were a final frontier, a slow curiosity about the smallest architects of the earth. He dug into soil and into age itself, confirming what Paul Celan would later crystallize in poetry:

There was earth inside them, and they dug.

Darwin’s late life curiosity was not about conquest but about humility, the patience to follow small questions wherever they led.

So too with Michelangelo, whose last sculptures—the unfinished Rondanini Pietà—show the great master chipping away at marble almost until the day he died at eighty-eight. Gone were the muscular certainties of his youth. What remained was a restless, trembling exploration of form dissolving into spirit. Figures blur, limbs elongate, stone seems to sigh. This was curiosity turned inward, the artist asking: what remains when mastery fades? It was less triumph than question—curiosity as chiseling into mystery itself.

And then J.M.W. Turner, nearly blind, staggering into the London fog of his late years. His paintings in the 1840s dissolve into storms of light and color—Rain, Steam and Speed, the Sea Battles, his almost abstract sunsets. Critics scoffed that he had lost his way. But Turner’s late canvases were curiosity made incandescent: a refusal to paint what he had already mastered, a hunger to see how light itself might undo form.

Turner’s brushstrokes became metaphors for perception itself, daring us to see the world not as fact but as possibility.

But curiosity does more than keep the brain agile—it preserves identity. In their research on learning among older adults, Kim and Merriam discovered that curiosity is inseparable from purpose. “Older learners do not learn to pass time,” they note. “They learn to affirm who they are becoming.” Susan Krauss Whitbourne echoes this in Curiosity and the Aging Self: “Curiosity allows older adults to stitch together continuity and change, to make meaning of both what has been and what is still possible.” To be curious in later life is to declare: I am not finished. Rilke, in Letters to a Young Poet, insists:

The future enters into us, in order to transform itself in us, long before it happens.

Curiosity in age is not nostalgia but preparation—the invisible pressing inward, asking us still to change. Or, in his famous imperative:

You must change your life.

Of course, the dark side cannot be ignored. Curiosity lures us not only toward symphonies and languages but toward car crashes and scams. Morbid curiosity is what slows traffic by the wreck. Online, it is the bait behind headlines—You won’t believe what happens next—that seduces us into click after click. For older adults, whose craving for resolution may make them less discerning, curiosity can become a liability, leaving them vulnerable to fraud and misinformation. As the Innovative Aging time-sampling study revealed, curiosity in older adults fluctuates with anxiety: high levels of uncertainty can sharpen curiosity, but they can also corrode judgment. “The desire to resolve tension,” the study concludes, “can make older adults more vulnerable to accepting simple but false answers.”

Still, to dismiss curiosity for its risks would be to dismiss fire for its burns. The great artists and thinkers carried it as both burden and gift. Goethe, scribbling in his eighties, remained restless as a student. Toni Morrison published novels when most of her peers were content with memory alone. Frank Lloyd Wright designed the Guggenheim Museum at ninety. Their curiosity was not a refusal to age, but a way of ageing differently—turning each year into another aperture rather than another wall. T.S. Eliot gave it a timeless formulation:

Old men ought to be explorers.

And in his final Quartet:

We shall not cease from exploration
And the end of all our exploring
Will be to arrive where we started
And know the place for the first time.

Curiosity does not deny mortality; it loops us back to origins, reframed by age.

Paul Celan’s fractured lyricism captures the moral weight of this work:

Speak, you too, speak as the last, have your say.

In old age, curiosity is no longer optional—it is the last duty, to remain open, to refuse silence.

One elderly woman, at ninety-one, could often be found hunched at her kitchen table, teaching herself Spanish verbs from a battered paperback workbook. She would never travel to Madrid or Mexico City. She was not chasing utility. She wanted the taste of a new language in her mouth, the satisfaction of puzzle and pattern. When she forgot the word for door in English, she would still smile at having remembered puerta. Her curiosity was not a guard against ageing; it was ageing done with grace. Her curiosity, like what Sakaki and Murayama call a “proxy for adaptive aging,” became her measure of resilience, even in decline.

Curiosity is also spiritual hunger. John Donne, caught in his paradoxes, reminds us:

Be thine own palace, or the world’s thy jail.

To age without curiosity is to dwell in the jail of repetition; to age with it is to build palaces of interior richness. And in the Holy Sonnets, he whispers across centuries:

When thou hast done, thou hast not done, for I have more.

Curiosity ensures that even at the edge of life, there is always more.

So is curiosity the key to ageing well? The podcast hedged. Scientists prefer caution. Yet what their data suggested was less a key than a posture, a way of leaning into the world. Curiosity keeps us not young, but alive to the present. It prevents the slide into cynicism, the sense that we already know what the day will bring. To be curious is to keep finding the world strange and therefore worth waking up to. Or as Whitbourne writes, “Curiosity is the stubborn insistence that the story isn’t over yet.” Stevens, Eliot, Rilke, Donne, Celan—they all converged on the same truth: curiosity in age is not ornament but essence.

The riddle that opened the podcast lingered across the episode like a withheld gift. Where do trees grow with square trunks? Not here, not in the daily landscape we take for granted. They grow in Panama’s Anton’s Valley, a reminder that the world still offers unlikely geometries if we are willing to ask. Perhaps that is the true answer: curiosity does not smooth the years or extend the clock. It gives us square trees in a round world, a glimpse of wonder tucked inside the ordinary. And maybe that glimpse is enough.

THIS ESSAY WAS WRITTEN AND EDITED UTILIZING AI