Written in the voice of a truly horrible waitress. One who is always worried about her tips, calculating what they should be when she should be focusing on her customers. Some people will stiff you. Deal with it. If you provide professional service, without regard to how you think they will tip, or how they have tipped in the past, your tips will take care of themselves. Trust me, there are at least as many crappy waitresses as there are crappy customers, and very often they end up getting tipped 20% just because it's expected, so it goes both ways. If you don't like your career choice, get another.