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?
Met a girl while being an English teacher in China. She was originally from New York. She had a very distinctive voice, very hard to forget.
Fast forward 10 years. I'm at the Santa Monica Pier playing Pokemon Go with my brother. Suddenly, THAT VOICE. I'm like... No... That isn't possible. I keep on walking.
We reach the end of the pier, and turn around. And BOOM. There she is. We make eye contact, and are both like wtffff.
Turns out she moved there to do a podcast or something.