Henry Muhumuza

The average human lifespan today is about 73 years. If you asked anyone how many people a 73-year-old has met, you'll usually get an answer in the hundreds or low thousands. "About a thousand" is the most common resting place. It sounds large enough to feel serious, and small enough to feel human.

The number obviously depends on occupation, geography, and temperament. Politicians and activists are outliers and distort the distribution, so they are excluded. I am interested in the average man.

Before counting, the term meeting requires definition, or else we risk going on a wild goose chase. Passing a stranger on the street does not count. Neither does the bank security guard, the pharmacist, nor the market man or woman who sold you vegetables once. These are collisions rather than encounters.

Meeting someone, for our purposes, means repeated exposure over time: enough to recognize them, enough to place them in context, enough that influence is possible.

Strangers can still alter a life meaningfully. A violent stranger who breaks into your home and kills your family has more influence than a hundred friends combined. One interaction, one event, and the rest of your life reorganizes itself around loss, fear, compensation. But such events are outliers. They matter existentially rather than statistically.

Occasionally, a stranger in a book does the same. You may never meet the author, and yet a single book you happen to read changes your worldview permanently. That stranger occupies a slot in your persistent influence network, rare as they are.

So we count persistent encounters.

UN data shows that roughly 45% of the world's population lives in cities, 36% in towns or suburban areas, and 19% in low-density rural areas. At first glance, this suggests that the average person is more likely to be urban. However, cities are concentrated in specific regions, often in high-income countries, while towns and suburbs are far more geographically widespread across low and middle-income countries.

Also, the distinction between a large city and a moderately sized town matters less than you might think. Social circles in cities are constrained by the same mechanisms as in towns: neighborhoods, workplaces, schools, and family networks. The routing logic is identical. Whether you live in Kampala, Los Angeles or a town of 50,000, your encounter set is shaped by institutional overlap and intersection of routines, not raw population density. The difference between meeting 2,000 people in a city of 2 million versus 2,000 people in a town of 100,000 is mostly symbolic. For practical purposes, the average person we are using is town-raised in structure if not always in geography.

Let's get into the numbers.

By age 12, most people have accumulated a surprisingly large encounter set. Immediate and extended family typically accounts for 20 to 30 people. Primary school introduces roughly 30 classmates per year over six years, with partial turnover, yielding about 100 distinct peers. Add teachers, neighbors, parents of friends, and community figures, and the number approaches 200. Conservatively, childhood contributes 180 to 220 persistent encounters. I went to a particularly small primary school and these numbers don't speak to my personal experience, but hey, I'm writing with the average man in mind.

Adolescence accelerates accumulation. Secondary school cohorts are larger, social circles widen, and friends of friends become relevant. A typical secondary school might expose a student to 200 peers across several years, with about half becoming persistent enough to count. Add extracurriculars, religious groups, and neighborhood expansion, and adolescence contributes another 250 to 300 encounters. By age 18, the running total is around 450 to 520.

Early adulthood is the most socially dense phase of life. University, vocational training, or early employment introduces hundreds of age-matched peers encountered daily. A single cohort can easily contain 300 people, of whom perhaps half are encountered persistently. Add roommates, romantic partners' networks, and secondary spillover, and early adulthood contributes 400 to 500 encounters. By the mid-twenties, the total sits around 900 to 1,000.

After this, the curve flattens.

From roughly age 25 onward, encounter accumulation becomes linear rather than explosive. Workplaces stabilize. Social circles repeat. You still meet new people, but slowly. Assume, generously, 2 to 3 new persistent encounters per month: coworkers, collaborators, clients, neighbors. That is about 30 per year. This is where the effect of temperament shows up. If you're like me: not outgoing and not fond of lingering in rooms designed for networking, even 30 per year feels optimistic. But let's keep it.

Over 35 years of working adulthood, this yields 1,050 encounters. But not all persist. Workplaces reorganize and former colleagues scatter. Of the 1,050, a realistic retention rate sits around 60%, accounting for moves, job changes, natural drift, and the simple fact that many professional relationships do not survive context shifts. That leaves 600 to 650. Late adulthood contracts exposure further but does not eliminate it. Healthcare providers, community members, extended family growth, and neighborhood turnover add perhaps 100 to 150 more.

Add the stages together and the lifetime total settles between 1,600 and 2,000 people.

That is the average truth.

So what does this number actually mean for the friendships we can have in a lifetime?

Jeffrey Hall's work on friendship formation provides a rare quantitative anchor. Turning a stranger into a casual friend requires roughly 50 hours of interaction. Turning them into a simple friend takes around 90 hours. Turning them into a close friend requires approximately 200 hours.

Across 73 years, the total social time budget—the time spent on making friends is not uniformly distributed. Infancy and early childhood contribute essentially nothing to discretionary friendship formation. Middle childhood through adolescence (roughly 6 to 18 years) offers perhaps 1.5 hours per day over 12 years (~6,600 hours). Early adulthood peaks at 0.75 hours per day over 7 years (~1,900 hours). Prime adulthood sustains about 0.5 to 0.75 hours per day over 30 years (~5,500 to 8,200 hours). Late adulthood declines to 0.5 hours per day over 18 years (~3,300 hours). The lifetime total is roughly 17,300 to 20,000 hours.

Divide this by the 1,600 to 2,000 people you meet, and each person receives an average of 9 to 13 hours across your entire life. But time is not distributed evenly. Most people get far less than the average. A few get vastly more. If you allocate 90 hours each to reach simple friendship, you can sustain roughly 190 to 220 simple friends over a lifetime (17,300 to 20,000 ÷ 90). More realistically, accounting for natural drift, falling out, and relocation, you retain 20 to 40 at the simple friend level. At 200 hours per close friend, the theoretical maximum is 86 to 100 people (17,300 to 20,000 ÷ 200). In practice, you sustain 5 to 10 close friends. Best friends, requiring sustained investment over decades, number 1 to 3.

This count matters because opportunity moves through people. Jobs, ideas, capital, exits, warnings, leverage. None of these appear spontaneously. They propagate through social edges. If the graph is narrow, opportunity is narrow. If the graph is homogeneous, opportunity is repetitive. This is why environment acts as a ceiling rather than a background variable. If no one in your encounter set has crossed a certain economic, institutional, or intellectual threshold, that threshold is unlikely to enter your future.

The internet changes where you meet people and which kind, not the constraint. Geography matters less, but the hours required for real influence remain unchanged. 200 hours is still 200 hours, whether accumulated in person or across video calls and text threads. Most digital encounters never reach that threshold. They remain lightweight, low-commitment, and interchangeable. The platform makes initiation cheaper but does not make deepening faster. Occasionally, someone remote enters your life who would never have appeared otherwise. When it works, it works completely. But the base rate stays low. Digital abundance creates the illusion of expanded access while leaving the structural bottleneck untouched.

So, in a lifetime, you will meet only a few thousand people. Most will remain acquaintances. Many will be perfectly pleasant. Some will be vaguely familiar forever. You will deeply know only a few. And the vast majority of what you become will be shaped by whoever circumstance placed within reach.