This refers to when two or more people encounter each other in completely coincidental fashion. You might notice your old classmate from three countries away is now your waiter in a place you had no reason to expect them in, and you might say "wow, what a small world". You might notice two people who you know from completely different spheres miraculously know each other. You might recognize by chance that your penpal has made a cameo at a venue you're at.
But what was your most profoundly coincidental encounter?
I have a few:
back in University I overhear some classmates I was not very familiar with talking about a girl playing Street Fighter IV competitively. They say the nickname. She was a girl I was flirting online with. I never played that game, she was from a completely other part of the country, she had no connection with my uni or the discipline of the uni. I asked her for confirmation and she said she knew the two guys, so it was actually her.
recently: I'm talking to a girl I met after being in contact on Facebook for 10 years. She's living in Paris, I'm living in Germany but we are both from Italy. Talking about an ex of mine, I ask her if she knows X because X and my ex have been together for a while. There was a slight chance she would have some kind of connection to him, but she says no, never heard of him. Then I start describing the guy, because he's the most toxic guy on the planet and there are a few very clear identifying informations. She says: "Ah, yes, I know the guy, I matched with him on a dating app when I was on vacation two years ago, he was nuts".
one time I was hanging out with my friend G. I'm talking about my political activity as a general mutual update on how we are doing, and I mention among other things how I was trying to reach out to a few very specific publications which cover labor stuff in Italy. G is a painter, not really active in politics except very local community stuff. They say: "wait, you said xxx media? The editor-in-chief is my sister. Mind=blown". To add to this, I have known G for like 10 years and I never really registered they had a sister.