Specific situation that boils me: you're in a restaurant with more than a couple people, the check comes, and people start to hand money over. The bill is covered, with a generous tip, and SOMEONE wants to discuss if it's not too much of a tip - SOMEBODY must have put TOO MUCH in and should get some money BACK! It's covered - what business is it of yours how much everyone else tossed in? God forbid the waitress could maybe take a cab that night instead of waiting for the bus.