When 2 of your friends somehow know each other, and from your perspective, its so random and feels like there's no way they could've known each other ever.
(Patrick seeing Jane and Nathan walking together)
Patrick: ...what?? how do you two know each other. you're both from two completely different groups and classes.
Jane: We both work at Subway.
Nathan: And we go to the same church.
Patrick: ......WTF. Never thought you two would know each other. Damn random Friend Wormholes.