For starters, the very job title describes how tough a waiter's job is. Someone who 'waits on people'. It can be tiring and annoying and frustrating and, for the peanuts that they get paid, they show a great deal of patience while putting up with all the shit customers give them.
While we barely make it on time for work, waiters keep up with many deadlines on a daily basis! How about we learn something here?
They say patience is a virtue and attaining it not easy, but waiters have somehow mastered the art. They put up with all the tantrums customers throw!