Sonder and loss of interaction
There are eight billion people currently alive, yet I've probably only encountered a million at most in person, and even that's an optimistic estimation. That includes people I regularly talk to, people I regularly see, people I have seen abroad, people who have walked past me on the street, people I have sat next to in a stadium, the like. I wouldn't be surprised if the actual number is far less than a million, but it does feel like it sometimes.
In my sixth form, I probably only regularly talk to about 20% of people in my year group. That's a very rough estimate, and since my year group isn't that large, it is also a meaningless statistic, but it puts into context how many people you may meet that you'll probably forget about. I no longer talk to anyone from my primary school, for example, including those who I considered friends, merely because time has passed by and we won't have anything in common anymore.
There will always be the odd people who you meet very often - checkout staff, regular transport users - but outside of that context, you've probably never crossed their paths. You don't actually know what's happening in their lives, and neither do they know what you're doing.
Sonder is a word that describes this feeling of realising that people around you have their own ambitions, thoughts, relationships, entirely separate from you, and it's a bit overwhelming to me to consider just how irrelevant one truly is when you remember they're like everyone else - no one is a main character, instead everyone merely spends their time on earth in relation to someone else. Eventually, we will all die, and eventually we will all be forgotten, yet people will continue living, as they have done before us.