Not mine, but my dad’s that I was there to witness.
It was summer (90s) and we were all camping at a lake. My sister and I were playing with some kids while my dad was chatting up the other kids’ dad. Just as I was getting out of the water I hear the other dad exclaim “you remind me of a guy I used to know called [name]!” My dad laughs and says “I am [name].” Turns out they used to go to school together decades before.
It’s stuck with me all these years, and has somewhat been turned into an inside joke within our family.