There is a gesture my best friend makes when she's listening carefully, a slight tilt of the head, eyes going a little soft. I caught myself doing it last week, mid-conversation with someone else entirely, and I froze for a second. It wasn't mine originally. I borrowed it over the years of watching her listen to me.

The self we experience as singular and continuous, the one we protect and explain and carry through the world, is assembled from an enormous number of people. We think of identity as something we build from the inside out. But identity is also built from the outside in over a whole lifetime, by everyone who has ever stayed close enough to leave a mark.

This is not a weakness or a lack of originality. It is, in fact, exactly what makes us human.

Neuroscience has a name for part of this: mirror neurons, a system in the brain that activates not only when we perform an action but when we observe someone else performing it. When we watch someone reach for a cup, our brain rehearses the act of reaching for the cup. When we see someone in pain, something in us registers pain. We are built, at a neurological level, to absorb and echo each other. This is the biological infrastructure of empathy, yes, but it is also the infrastructure of influence. We are literally wired to adopt the patterns of the people we spend time with, from movement to speech rhythms to emotional responses.

Psychologists call a related process "internalization," which is what happens when someone who was once outside us becomes part of how we think. The clearest example is the early caregiver: children internalise not just behaviours but entire relational templates, ways of expecting to be treated, ways of treating others, ways of understanding what love looks and feels like. But internalisation doesn't stop in childhood. It happens whenever we're in close contact with someone long enough. The boundary between self and other is more porous than we like to think.

It's worth noting that the idea of a self that is autonomous and separate and fundamentally individual is a relatively recent and geographically specific invention. For most of human history, and for most of the world today, selfhood has been understood as inherently relational. The Ubuntu philosophy from southern Africa, most commonly translated as "I am because we are," holds that a person becomes a person through other people, not despite them. This is not a poetic metaphor. It is a literal description of how things actually work. The Confucian tradition in East Asia similarly understands identity as emerging through relationships and roles, not in isolation from them. Even in the Western philosophical tradition, Aristotle held that humans were by nature social animals, that a person living entirely outside of community was either a beast or a god.

The hyperindividualist self, the one who is self-made and self-sufficient and answerable only to their own interior, is a fairly lonely and fairly recent idea, and there is a growing body of research suggesting it's also making people genuinely unwell.

What I find astonishing about all of this is how accidental it is. You did not choose most of the people who shaped you. You didn't choose your family, obviously, but you also didn't choose that particular teacher, or the friend you happened to meet because of a scheduling mix-up, or the person you sat next to once on a long flight who said something you still think about. The mosaic of who you are was assembled partly by luck, by proximity, by timing, by the particular coordinates of your life.

This could feel destabilising, but it can also be genuinely moving. It means that small encounters matter more than we think. A single conversation, arrived at by accident, can reroute something in a person. A single gesture of generosity can become a standard someone carries for decades. We transmit things to each other without knowing it, which extends beyond what we can see.

There is a comfort in understanding selfhood this way when it comes to grief. When someone we love dies, the language we reach for is almost always about absence, about the space where they were. But something else is also true: the people we have loved and lost do not simply cease to exist when they stop living. They continue inside the people who knew them, in gestures and phrases and habits of mind, in the specific way someone holds a coffee cup or tells a certain kind of joke or insists on a particular kind of kindness. The people we have loved become part of the material we're made of. They travel forward in us.

This is not a consolation prize for grief; it doesn't make the loss smaller. But it does make continuity larger than we tend to assume.

If we are mosaics of everyone we've encountered, then we are also becoming part of other people's mosaics right now, whether we intend to be or not. Every interaction is a small transmission, and none of them evaporates. It goes somewhere. It lands in someone and becomes part of how they move through the world.

Now, this is not a call to perform goodness, to be relentlessly meaningful in every exchange. Most exchanges are ordinary and should be. But it is worth knowing that ordinary exchanges are not neutral.

All of us are walking archives of everyone we've loved and lost and briefly encountered and been changed by. A record of everyone who stayed close enough to matter. The self is not a fixed thing that exists prior to relationship and then goes out to engage with the world. It emerges from a relationship, continuously, over a whole life. It grows wider and more intricate and more capable of recognising itself in others precisely because it has been so thoroughly shaped by others.

We contain multitudes.

I probably had it once; that elastic, slow, tender way of looking at the world where everything was potentially interesting and nothing was too small to stop for. A ten-minute walk turned into forty-five because there was a beetle on a sidewalk, or a crack in the pavement shaped like the mango tree in the backyard.

When did I wake up and decide that beetles were boring and cracks in pavements were just damage and the world was mostly a series of tasks to get through? Like eating when you're not hungry, it's fine. That's what it all is. When did I stop stopping? When does wonder go? When did I quit tending it? What is it about adding numbers to one's age that makes life lose its charm?

Wonder became the territory of children and artists and people who have too much time on their hands. The rest of us learned to be efficient, to process the world quickly and move on, to see something and immediately decide what to do with it, file it away, or scroll past it. We learned to manage our attention rather than give it. Some of the most wonder-filled people I've encountered are also some of the most knowing, the most experienced, the ones who have seen enough of the world that they could easily be cynical but somehow aren't. And I envy them. I, too, want to see things and make a different choice about what to do with what I've seen.

I, too, want to be as courageous and open, and not let disappointment accumulate as a reflex response. When it's easier to stop being surprised and just know how most things will go, I want to look at life as if it were the first time. Not just in the presence of worthy subjects, cathedrals, mountains, and great works of art. I want to experience wonder in a cloud, in the smell of something, in the hand of someone, or in the sun coming through the car window.

I want to ask questions and not get answers, and not mind it.