Our whole society has this dual concept of treating customers like royalty and workers like shit. So it gets pretty bad.
My job was pretty bad until i got promoted. I worked recycling centers, often alone. People think they can treat us like garbage and we're responsible for keeping everything in order. Gotta make sure the line is orderly, no one's cutting, and everyone is actually in line. Gotta make sure barrels go out in the order of the line because there's not enough for everyone to have what they need.
People get real ugly when you tell them what to do. Then you gotta tell them they didn't get what they thought they were for their cans because they guessed wrong or "last time i got more!".
Basically you gotta piss people off all day. I got used to it. You learn to project an air of command and be assertive. It helps usually when folks realize you don't care what they want.