It's hard being a waiter. The pay can be low, the hours are long and certain customers can be especially irritating. On the flip side, for those customers that are actually polite and pleasant, having an annoying waiter can ruin the dining experience.
First We Feast has put together a good compilation of the annoyances customers have when dealing with restaurant staff. Take a look -- we're guessing you can relate to several (all text courtesy of First We Feast).