A personal anecdote: when I was a student in CS, back in the early nineties, I was working in a gas station the WE. A fellow student, now leading IT department

A personal anecdote: when I was a student in CS, back in the early nineties, I was working in a gas station the WE. A fellow student, now leading IT department in a European airport, was visiting me and we were chatting outdoor, just nearby the little shop I was in to cash. And then he lights a cig. I asked him if he was ok doing that in a gas station, and he responds me something like well, we are far enough (and that was true, but still) And when he finished it, he dropped it on the ground and scratch it with is foot : « You know I’m the one who’ll have to pick it to trash it, and then have to clean the black mark it leaved on the white cement, do you ? » « Oops, sorry » He is a person I respect for a lot of things, and one of the last friend from my student time. But his smoking M.Hyde side never stops to puzzle me.