Picture this. It's a Monday morning and you're heading to the station to catch your usual 7.52 train to work. Waiting for your train to arrive, you feel a sense of unease creeping through your body: this usually-crowded platform is completely empty.
The train arrives and you step in, easily grabbing your favourite seat because there is not another soul in the carriage. You are beginning to get really worried: has there been a national disaster and you're the only one who doesn't know?
You check the news on your phone. No crisis, it seems, so you continue on. You arrive at Central Station, and again, it's a ghost town. It freaks you out but you continue into work anyway, where you're relieved to finally see people—and furthermore, they are people who you know. You breathe a sigh of relief.
In our huge modern cities, we are used to being surrounded by people. The idea of going to work and not seeing a single person on our way is unimaginable–and yet, we put a lot of effort in trying to emulate that feeling of being utterly alone.
Us city dwellers have a whole repertoire of ways to pretend that we are the only person alive when we are actually surrounded by strangers. We fix our slightly-lowered gaze ahead of us in the direction we are walking. We refuse to look people in the eye. We hide behind books and phones to create social barriers, and we only talk with the people around us in the case of extreme emergency. Even then, we'd be more likely to phone someone than actually engage in direct conversation.
One nowhere feels as lonely and lost as in the metropolitan crowd.
Why do we do this? Why do we insist on isolating ourselves, and why do we believe that talking with strangers is the second sign of insanity?  After all, humans are very social animals; we get bored easily, and many of us complain about how difficult it is to make friends in cities. Are these antisocial urban habits some kind of adaptation to an unnatural life?
It might surprise you to know that this kind of urban behaviour isn't new. Not even close. In fact, it has been observed at least as far back as 1903, when the sociologist Georg Simmel wrote that 'one nowhere feels as lonely and lost as in the metropolitan crowd'. 
Part of that loneliness comes from being surrounded by strangers. Another part of the loneliness stems from the self-isolation methods that I described above. But Simmel argues that when our behaviour isn't due to sheer unsociability. Rather, he points out that when we wander through cities, we must ignore most of what is happening around us. If we didn't, we'd quickly end up with sensory overload and have a nervous breakdown.
If you don't believe me, go stand on a busy city street and try to pay attention to everything that happens around you. You'll see cars flashing by, lights blinking on and off, people brushing past within inches of your face, advertising messages everywhere, and lots of symbols to decode.
If the visuals aren't enough, try listening to all the different elements of sound that accost you: traffic, footsteps, music, people talking, phones ringing. And so it goes on.
What happens is that our physical bodies become accustomed to all these inputs and stop paying conscious attention to them. Instead, we focus on the task at hand: look ahead, move your feet, avoid obstacles and get to work. We also create social rules to deal with urban life, such as proscribing the proper ways to interact with those around us.
Talking with strangers increases our urban workloads, giving us more obstacles to navigate, and distracts us from what we are trying to achieve. We expect others to respect us by leaving us alone. In fact, we tend to get annoyed at other people for breaking the rules even when we aren't personally affected. This extension of concern to the world around us is proof of the sociability of our antisocial behaviour.
So, next time you're on a crowded train, or sashaying around downtown, enjoy the peace and quiet and leave other people in peace. Not only will you be behaving in a social way; it is possibly the only social setting where you will find yourself to be absolutely, truly alone.