The adult human brain contains somewhere between 86 and 100 billion neurons. Each of those neurons can form thousands of synaptic connections. For most of the twentieth century, scientists believed that after a certain point in childhood, the architecture of those connections was essentially complete — that the brain, and by extension the personality it shaped, was fixed.
That assumption turned out to be wrong. And the reason I find this so personally important is that I spent most of my twenties building a self-understanding on top of it.
I was someone who worried. Someone who found stillness difficult. Someone who needed external change, travel, novelty, movement, to feel properly alive. I knew these things about myself the way you know facts: not because I had chosen them, but because they had happened reliably enough to become categories. This is who I am. This is what I do. This is the finished version.
The problem with treating yourself as a finished product is that you stop asking which parts you assembled yourself and which parts you simply stopped noticing.
I knew the word neuroplasticity before I understood what it actually meant. For a long time I understood it to mean something like: the brain can recover after injury. Remarkable, but not immediately relevant to a functioning person with no injury to recover from. What I didn’t understand, and what shifted something when I finally did, is that plasticity isn’t only a recovery mechanism. It is the normal state of the brain throughout life. The connections are always being shaped. What changes them is what you do repeatedly, what you attend to, what you practice.
The maintenance mindset
The phrase that keeps coming back to me is one I came up with myself, which makes me slightly suspicious of it: I had been maintaining myself like a finished product instead of a living system.
When you assume your personality is fixed, the task becomes maintenance. Keeping the existing structure functional, managing its predictable failure modes, working around the things you’ve decided you cannot change. The project isn’t renovation. It’s upkeep.
I was maintaining a tendency toward anxiety by treating it as identity. Every time I caught myself worrying, I filed it under this is how I am rather than this is what I am currently doing. The distinction sounds subtle and is not. If the pattern is who I am, it belongs to the domain of self-acceptance. If it is something I am doing, a habit reinforced through repetition, it belongs to the domain of behavior, which means it belongs, at least in part, to the domain of choice.
The science of neuroplasticity, documented at length by neuroscientist Michael Merzenich, demonstrates that gray matter can shrink or thicken and neural connections can be forged, refined, or severed in response to what we practice. The brain does not wait for injury to reorganize itself. It reorganizes in response to ordinary experience, ordinary attention, ordinary repetition.
This means the patterns I had been treating as fixed features of my personality were, at the neural level, patterns being maintained. Reinforced through repetition. Not set in stone.
What changing actually looked like
I want to be careful here, because I am a psychology researcher, not a therapist, and this is not clinical advice. If you are dealing with anxiety or other mental health difficulties, talking to someone qualified is worth more than any article.
What I can describe is what the shift felt like for me, which was less like a transformation and more like a question I couldn’t stop asking. If this pattern exists because I keep creating it, what would happen if I didn’t?
Not what would happen if I just stopped, I am not naive about how behavior change works. But what would happen if I stopped confirming the pattern every time I noticed it? If, instead of filing the anxiety under this is who I am, I noticed it as a behavior and asked what it was doing there?
The answer, most of the time, was something like: a habit of scanning for risk in environments where risk wasn’t actually the relevant thing. I had been doing it so consistently that it had become automatic. The automatic felt like identity. Autopilot and identity are not the same thing.
Researchers studying personality change in adulthood, including a 2022 review published in Innovation in Aging, have documented that personality traits, though relatively stable across the lifespan, show meaningful change in response to environmental influences, life events, and deliberate effort. The notion that your personality at twenty-five is the one you’ll have at forty-five has not held up under longitudinal study.
Living like a system in progress
What I have settled into is less a program than an orientation. I try, with varying degrees of success, to treat my patterns as behaviors rather than as definitions. When I notice that I am avoiding something, or that a particular emotional response has become automatic, I try to stay with the question of whether it is still doing useful work, or whether it has become a habit that persists because habits persist.
This doesn’t feel like self-improvement in the motivational sense. It feels more like maintenance of a different kind: not upkeep of a fixed thing, but attention to a living one. The difference is that maintenance assumes the structure is complete. Attention to a living system knows it is always, to some degree, still forming.
I think about the phrase finished product and what it implies. Products get finished so they can be shipped. A living system doesn’t get shipped. It stays in process. The work of staying curious about your own patterns, not as a form of self-surveillance but as a form of honest attention, is different from the work of managing what you have already decided you are.
The realization has been, in quiet ways, one of the more useful things I have come across. Not as a revelation, but as a small and practical shift in how I relate to the person I seem to be at any given moment.
