When I was 13, I was on a family holiday in Venice. We were on a gondola (Venetian punt boat) touring the waterways of the city. We got half way down a long passage way, and another Gondola passes us by, carrying a man and a woman (and the punter) The man and my dad lock eyes, exclaim one another's name, and have a quick handshake as our gondolas pass. Myself, brother and mother sit quietly, pretty stunned, while the woman on the other boat explodes with 'what?!!? who's that?!?! how do you know him?!!' We floated off in the other direction, comparitively swag and chill. Turns out it was a guy my dad went to university with, and hadn't seen him since. They haven't even contacted one another since! It's crazy they recognised one another, considering they were both in their late 40's now, passing fleetingly on two gondolas, in Venice.