I hate it when we all go out to lunch and a few of my Co-Workers inevitably "forget" how much their tab is, or "forget" that they had a beverage, or "forget" about the tax, and don't leave a tip. They just throw down $5 and think that amount covers it all. I actually said "Oh, didn't you have the chicken parm sandwich? I think that was $8.99...and aren't soda's expensive?" (hint hint) I get a dirty nasty look when I point things out, but I am NOT about to pay for your dammmed lunch, you stingy parasite! You ate it, you pay for it!