It was at the cashdesk of a Supermarkt yesterday. "Rush Hour" during Easter Shopping. The woman beside me was confused wheter she was in front of me in the queue or not. Literally noone of us in the queue had known where it's beginning or end was...
I just let her go first, saying that i doesn't matter to me, because i'm not in a hurry.
I earned a big smile and a heartful "Thank you".