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?