You will never meet everyone. Not even close. And the math behind why is staggering.

The thought experiment

Assume a world population of 8 billion people. Assume an average human lifespan of 70 years. Now imagine you could meet one new person every single second, without sleeping, eating, or pausing for even a moment. You still wouldn't make it. 70 years is roughly 2.2 billion seconds. That's only about 28% of the world's population. To shake hands with every living person at one per second, you'd need around 253 years of nonstop introductions. Even at the absurd rate of 10 people per second, it would still take over 25 years, every second of every day, to get through the full 8 billion. It captures something we rarely stop to think about: we are surrounded by an almost incomprehensible number of people, and we will only ever interact with the tiniest sliver of them.

How many people do we actually meet?

Estimates vary, but most research suggests the average person meets somewhere around 80,000 people in a lifetime. That sounds like a lot, until you compare it to 8 billion. 80,000 out of 8,000,000,000 is 0.001% of the world's population. A study highlighted by Our World in Data found that the average American knows about 611 people by name. Even if you're unusually social and know 800 people, that's 0.00001% of the global population, a hundred-thousandth of a percent. As the researchers put it, if the world population were the size of a sheet of printer paper, the number of people you know would be the width of a single human hair. Meanwhile, research on facial recognition suggests that while we might see around 3 million faces over a lifetime, we remember only about 3,000 of them.

Dunbar's number and the limits of connection

Even the relationships we do form have hard limits. British anthropologist Robin Dunbar proposed that humans can maintain approximately 150 stable social relationships at any given time, a figure now known as Dunbar's number. This isn't about how many people you've met or how many contacts are in your phone. It's about the number of people you can genuinely keep track of, people whose lives, histories, and social dynamics you actively understand. Beyond that threshold, our brains simply run out of bandwidth. Some researchers have challenged the exact figure, suggesting it could be somewhat higher or lower depending on the individual. But the core insight holds: our social capacity is finite, and it's far smaller than our ambitions might suggest.

Six degrees of separation

Here's the counterpoint: the world is too big to know, but it might be small enough to traverse. In 1967, social psychologist Stanley Milgram ran his famous "small world" experiment. He asked people in Nebraska and Kansas to forward a letter to a specific person in Boston, passing it only to someone they knew on a first-name basis. The letters that arrived did so in an average of about 5.2 steps. The idea became known as six degrees of separation, the theory that any two people on Earth are connected through a chain of at most six social links. Duncan Watts and Steven Strogatz later formalized this in 1998 with their small-world network model, showing that even a few random long-range connections in an otherwise clustered network dramatically shrink the average path length between any two people. And Facebook's data team found that the average degrees of separation between users was about 3.57 as of 2016, suggesting the internet has made the world even smaller. You can try this yourself. A famous example is Steam, the gaming platform. Go to your profile, open your friends list, and click on the friend with the highest Steam level. Then go to their profile and do the same thing, click the highest-level friend. Keep repeating. Within six steps or fewer, you'll reach one of the highest-level profiles on the entire platform. You're literally watching the network's hub nodes act as shortcuts, each high-level profile connected to other high-level profiles, forming highways through the social graph. This illustrates a property called preferential attachment: well-connected nodes tend to connect to other well-connected nodes. It's the same principle that makes six degrees work in general. Hub nodes, whether they're popular gamers, social connectors, or influential creators, dramatically shrink the distance between any two points in the network. So while your direct reach covers a negligible fraction of humanity, your network reach is enormous. If each person knows roughly 600 people, then two hops out puts you at 360,000 people. Three hops, 216 million. Four hops theoretically exceeds the world population. The numbers get messy because of overlap (your friends' friends often know each other), but the core insight holds: the world is simultaneously too big to experience and small enough to navigate.

The compounding power of referrals

This network math has a practical consequence that most people underestimate: referrals compound. If you do good work for one person and they refer you to just two others, and each of those two refers you to two more, you don't get linear growth. You get exponential growth. After ten rounds of this, a single satisfied client becomes over a thousand. After twenty rounds, over a million. Of course, real referral chains don't sustain perfect doubling forever. People forget, life gets busy, and not every interaction produces a referral. But even a modest, imperfect referral rate creates growth that dramatically outpaces what you could achieve through cold outreach alone. This is why the best businesses, freelancers, and creators often spend less time marketing and more time delivering exceptional work. Every person you help well becomes a node in your network, a potential bridge to people you would never have reached on your own. You don't need to meet all 8 billion people. You just need to make a strong enough impression on the ones you do meet, and let the network do the rest. The world is too big to reach directly. But through the compounding effect of trust and word of mouth, your influence can travel far further than your personal bandwidth ever could.

Why this matters

It's easy to form opinions about "the world" based on what we see around us. Our coworkers, our neighbors, our social media feeds. But our personal experience covers an almost negligibly small fraction of humanity. This has a few practical implications:

The pie is always big enough

If the world is too big to know, it's also too big to saturate. No matter how large the market, no matter how dominant the existing players, there is always room for new competitors. This isn't wishful thinking. It's a direct consequence of the math we just walked through. Think about any industry: insurance, real estate, SaaS, consulting, food. The biggest companies in each space serve a fraction of the total addressable population. Even a company with millions of customers is reaching a tiny sliver of the 8 billion people on this planet, and an even tinier sliver of the businesses, communities, and institutions they form. The same logic applies to clients and customers. Whether you're selling a service, launching a startup, or building an agency, the pool of potential customers is, for all practical purposes, infinite. You will never run out of people who need what you're offering. You might struggle with distribution, positioning, or timing, but the demand side of the equation is never the bottleneck. We tend to look at crowded markets and assume the opportunity is gone. But that's the same cognitive bias at work: mistaking our small visible slice for the whole picture. The world is too big for any single player, or even a hundred players, to cover. Do not underestimate how many people are out there.

One step at a time

The sheer scale of the world can feel paralyzing. If you want to build something meaningful, change an industry, or push a vision forward, the size of it all can make the goal seem impossible. Eight billion people. Hundreds of countries. Thousands of industries. Where do you even start? You start small. You start with the people you already know. Every massive movement, every world-changing company, every cultural shift began in a room, a garage, a dorm, a group chat. SpaceX started with a small team of engineers who couldn't even get their first three rockets off the ground. Instagram launched as a simple photo app used by a handful of friends in San Francisco. Google was a research project between two PhD students at Stanford. None of them tried to change the whole world on day one. They changed their immediate circle first. Then their city. Then their country. Then their region. Then, eventually, the world caught up. This is how scale actually works. Not as a grand top-down declaration, but as a slow, compounding expansion outward. You solve a problem for one person. Then ten. Then a thousand. Each ring of influence builds on the last, and before long, what started as a tiny experiment has become something global. The world is too big to change all at once. But it's not too big to change one step at a time.

The world is too big, and that's okay

You can't meet everyone. You can't even come close. But that's not a reason for despair. It's a reason to pay more attention to the people you do meet, and to stay curious about the vast majority you never will. The world is too big to know, but it's not too big to care about.

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