I hate customers. Not all of them, I have my regulars that are very sweet. But the rest are jerks, I wish they'd give me their money, sit down, shut up, and go away in an organized and timely fashion. BUT NO they decide to track mud on my floor, get their own orders wrong, claim it's my fault, talk to my manager about how they're so much more important than the other 40 people in line, take a break from scarfing their face to drop a bomb in the restroom, smear mustard on my tables, forget that they put their kids in highchairs and left their infants on the other side of the restaurant alone, draw stupid smiley faces on my windows, say that they don't want ketchup when I'm standing there with a tray full of ketchup, and then come bother me to ask for ketchup, then complain about the service and swear they'll never be back only to show up the next day and do it again.
Just a note, be nice to the people who make your food. Remember, we make your food. Think about it.