Last weekend I was at Number Four Niece's Engagement Party and had one of those "we're not from different sides of the tracks, we're from different towns" moments.
The party was held on a Festiva boat - four hours of cruising around New York Harbor on a rather hot and humid Saturday night. It was really quite nice! Until... I was sitting there, and a groomsman (I knew that because he had a button that said "groomsman" on it) flicked a cigarette butt out into the water. Apparently I had my Librarian Face on, because he looked at me and said "c'mon, everyone does it".
Perhaps everyone does do it, but that doesn't mean that you have to. Or that you should. Or that everyone's right. As my mother and grandmother used to say, "if everyone jumped off a cliff..."