I have found, that in the chaotic world of a restaurant, there are a few constants (comforting or otherwise). They are:
There will always be customers who...
Are never satisfied no matter how much you bend over backwards for them.
Lie through their teeth to a manger just to get something for free.
Make bad jokes and expect you to find them funny.
Think that just because you're working in the establisment they've just walked into, you actually give a flying fart in space about them, their problems, their issues, what they came in for, what their baby's momma's cousin's nextdoor neighboor's babysitter's hairdresser's opinion of the establisment is; they think that they can treat you like crap, expect you to take it with a smile, and are angry when you don't.
Believe because it's not their house, they don't have to clean up after themselves.
Think that "there are people who are paid to do this" when in reality, there is no special position open to unclog toilets and pick random cigarette butts and pieces of paper up off the floor, no matter what universe you live in.
Think they're always right, you're always wrong, and because they are simple the best customer in the world, they deserve everything for free.
Think that it's okay to hit on you to try and get what they want.
Lie about calling ahead and become "angry" when you do not have their name on the list.
Try and weasel their way into getting seated sooner.
Ask how much longer it will be for them to wait, after waiting for ten minutes. Do the math people!
Complain that they've been waiting long than they really have.
Shift the blame to you for their stupidity, incompetence, or total ignorance of anything outside their range of comprehension.
Believe that they are never in the wrong no matter what they do, it's always one of the employees' fault. (Yeah, it's the employee's fault that you ordered steak instead of chicken like you "really wanted" when you really just changed your mind after the server took your order and felt you could get a free meal out of it!)