My dad turned seventy this year.
The thing I’ve been quietly watching, in him and in his friends, is how differently people are aging. Some of his oldest mates have gone foggy. They repeat themselves. They’ve stopped picking up new things. They’ve narrowed their lives down to a few familiar tracks and seem mildly suspicious of anything outside them. My dad, on the other hand, has somehow gotten sharper. He’s reading more than he did at fifty. He’s into podcasts about subjects he had no interest in a decade ago. Last Christmas he was peppering me with questions about AI, of all things, with the energy of a teenager who’d just discovered something.
I used to think the difference was genetic. Or diet. Or some lucky neurological draw.
The more I’ve looked into the research, and the more I’ve watched older people I know up close, the more I’m convinced the difference is something simpler and more beautiful than any of that. The brains that stay sharp into old age have one thing in common, and it isn’t supplements or sudoku. It’s that the person inside them never stopped being genuinely curious about things.
The science on this is more direct than I expected.
What the research actually shows
A 2018 review in Neuroscience and Biobehavioral Reviews, led by psychologist Michiko Sakaki, brought together a wide range of evidence on curiosity in old age. Their conclusion was striking. Curiosity, they argued, plays a critical role in maintaining cognitive functioning, mental health, and physical health in older adults. They tied it to specific brain systems involving dopamine and norepinephrine that remain active when people are pulled toward something they find interesting.
In other words, curiosity isn’t just a nice personality trait. It activates the exact neural systems that keep memory and learning intact.
More recent UCLA research led by psychologist Alan Castel has found something even more interesting. While general curiosity tends to decline with age, specific curiosity, or “state curiosity,” actually increases later in life in healthy older adults. The people who keep getting interested in particular things, the ones who fall into rabbit holes about Roman history or birds or jazz or how the brain works, seem to maintain memory function better than peers who don’t.
There’s a related finding in the personality literature. Longitudinal studies have repeatedly linked the personality trait of openness to experience, which is essentially curiosity in trait form, with better memory and slower cognitive decline. A study published in Social Cognitive and Affective Neuroscience found that older adults higher in openness showed better episodic memory performance, partly mediated by better preservation of the brain’s memory network.
The pattern is consistent across studies. Brains that stay engaged with novelty hold up. Brains that don’t, don’t.
Why brain training apps mostly miss the point
Now, here’s where it gets uncomfortable for the wellness industry.
A lot of older people I know have been sold on the idea that they can drill their way to a sharper brain. They download Lumosity. They do daily sudoku. They take supplements with optimistic packaging. Some of them are doing it dutifully, joylessly, like a chore. They believe they’re doing the right thing because they’ve been told this is what keeping your mind sharp looks like.
The research on brain training apps is, at best, mixed. A 2025 paper in the European Journal of Psychology found that computerized brain training has limited cognitive benefits in healthy aging, with most gains being narrowly task-specific and rarely transferring to real-world cognitive function. You get better at the game. The improvements often don’t follow you into your actual life.
That doesn’t mean apps are useless. They probably have some marginal value for some people. But there’s something off about the underlying premise. The premise is that you can substitute genuine engagement with a regimen of artificial engagement, and get the same result.
You can’t.
A regimen done out of obligation activates a totally different psychological state than a curiosity pursued for its own sake. Drilling against your will is closer to surface-level repetition. Diving into something because you genuinely want to understand it activates the dopamine system, the memory system, and the parts of the brain that consolidate learning. Same activity on paper. Completely different result inside the brain.
The cruel irony is that the people most likely to download a brain-training app and use it religiously are often people who lost their curiosity years ago. They’re trying to compensate for the missing thing rather than addressing it directly.
What my dad does without realizing he’s doing it
When I look at my dad, he’s not on any regimen. He’s not doing crosswords because he’s worried about Alzheimer’s. He’s reading a book about the history of monetary policy because, for some reason known only to him, he finds it fascinating. He’s started watching woodworking videos on YouTube. He learned to use WhatsApp at 67 because he wanted to talk to his grandkids more easily. He asks me to explain what I’m working on, not as polite small talk, but because he actually wants to know.
None of this is for his brain. It’s for him.
I’ve talked about this before but the difference between doing something for its own sake and doing something because you’re supposed to is one of the most underrated distinctions in psychology. The brain knows the difference, even when we pretend it doesn’t.
My dad’s friend, who’s exactly the same age, is the opposite. He stopped being curious about anything new sometime in his fifties. He watches the same channels. He has the same conversations. He’s not unintelligent. He’s just emotionally closed to anything unfamiliar. And his memory, slowly but undeniably, is going.
I’m not a doctor. I’m not making clinical claims. But the contrast between these two men, who started in roughly the same place fifty years ago, is so stark that it’s hard to ignore.
Why curiosity quietly dies in most adults
Here’s the part that should concern people my age, in our thirties and forties.
Curiosity rarely disappears in old age. It usually disappears decades earlier and just becomes more visible later. The retiree who can’t be bothered to learn anything new isn’t suddenly that way. He’s been that way since he was forty-five and stopped picking up new books, since he was fifty and started saying things like “I don’t really do technology,” since he was fifty-five and treated every unfamiliar idea as an inconvenience.
What kills curiosity in middle age?
A few things, in my experience. The exhaustion of work and parenting. The hardening of identity (“I’m not the kind of person who reads that”). The smug certainty that comes with having figured out a few things. Social environments where being interested in unexpected things is faintly embarrassing. The slow narrowing of one’s information diet to whatever feels comfortable and confirming.
Each of these, on its own, is small. Together, over a few decades, they build a brain that’s pulled toward almost nothing new.
The good news is that curiosity is a muscle, not a fixed trait. The same Sakaki review I mentioned earlier emphasized this point. Curiosity can be reactivated at any age, and the neural systems that respond to it remain available even in older adults. Your dad in his sixties can still develop a sudden interest in birds. Your aunt in her seventies can become a podcast obsessive. The capacity is still there.
But it has to be exercised by being interested in actual things, not by drilling on artificial puzzles designed to substitute for being interested.
The Buddhist version of this
There’s a concept in Buddhist practice called beginner’s mind. The idea is to approach things with the freshness and openness of someone encountering them for the first time, regardless of how many times you’ve actually encountered them.
For most adults, the opposite happens with age. The mind hardens into expertise. You stop seeing the thing in front of you and start seeing the category you’ve sorted it into. A flower becomes “a flower.” A new technology becomes “another one of those.” A young person’s passion becomes “I’ve heard this before.” The mental shortcuts save energy. They also kill the part of you that learns.
Mindfulness practice, which I’ve leaned on for years, is essentially a discipline of noticing. Of staying available to the actual thing, even when your brain wants to file it away. It turns out this is also, almost incidentally, one of the most cognitively protective things a person can practice.
The brain that keeps being interested in the world is the brain that keeps being able to take it in.
Final words
If you have parents or grandparents in their sixties or seventies, watch them for a week.
Notice which ones are still asking questions. Which ones are still picking things up. Which ones light up when their grandkids talk about something the older person doesn’t understand, versus which ones look mildly threatened by the unfamiliar.
You’re watching the divergence in real time. The first group is, on average, going to age much better than the second.
If you’re younger, watch yourself with the same honesty. When was the last time you fell down a rabbit hole about something purely because you wanted to? When was the last time you read a book outside your usual lane? When was the last time you let yourself be a beginner at something?
Your future memory doesn’t depend on supplements or apps. It depends on whether you’re still the kind of person who finds the world interesting.
The simplest cognitive insurance policy in the world is to keep being genuinely curious about something. Anything. Pick the topic that calls you, not the one you think you should care about. Follow it as far as it goes. Pick another one when that one fades.
Most people stop doing this in their forties without noticing. The ones who don’t, the ones who keep falling into new things their whole lives, are the ones whose brains keep showing up for them.
It’s a much kinder regimen than the alternative. And it’s the only one the research really backs.
