Have you ever made fast friends with someone you'll probably never see again?
I don't mean polite small-talk so they won't think you're rude. I mean real sharing about life experiences and feelings, to the point that you actually begin to care for the person and you're truly sad when time is up and you both to go separate ways a mere 24 hours after meeting.
It's happened just once to me. It was the strangest thing, in a bitter-sweet kind of way.