I thought of this question because someone joked about double-dipping their hands in the chocolate fountain at Golden Corral and boy did that invoke one of my least favorite paying-for-college memories.
Yes, someone did dip his hands into the chocolate fountain at the Golden Corral. Worse, he was a repeat offender, a man that was at least in his 30s if not older slurping it off of his fingers and all, sometimes while making eye contact with me or my coworkers. Worse, there was no enforced rule against doing so, at least at my location, so my manager just told me to let him do it, don’t make a big deal out of it, and hope he doesn’t bother anyone else.
That same manager once insisted on me making the place extra clean a little before Christmas, so they insisted that I use double the amount of cleaning bleach in the same bucket. I explained that’s not how cleaning works or how OSHA compliance works. I got a write-up. I said that wasn’t an offense that qualified for a write-up, and what they said was “thanks for the tip, I’ll find something that is. Your word against mine.” 
That same manager punched me out early without telling me, because the place wasn’t perfect enough before I left over an hour late, missing my family waiting to pick me up outside by that long to go out to do holiday stuff. I did call that in on the supposedly anonymous tip line later, but you can guess what happens when an anonymous tip about wage theft is called in on a manager that already knows who would call in that tip in a “right to work” situation. 
That same manager was fired a week later for embezzlement, and not the cool kind. They were writing up and firing people for months for money missing from the register. I found out when collecting my last check and noticed someone new. 
I’m sure I could think of more if I tried but I remember the first time during my first job that I realized customers will tell you to do things simply because they want a servant to perform arbitrary tasks for them and they’re willing to lie to or guilt trip strangers just for the rush of bossing somebody around.
I was working as a cashier and some lady went to pick up a bag and lifted it 3 inches before going “Ah” and her wrist gave out and dropped the bag. She wanted me to take some items out and put it in a separate bag because it was too heavy. At that moment it was no problem, I simply took half the stuff out and placed it in a separate bag. She then grabbed both bags in one hand and effortlessly lifted them into her cart.
It was such a short and meaningless interaction but I wanted to punch my register’s screen as hard as possible and quit right there but I just pretended like it didn’t happen because it was the end of the order. After that I started to notice all the little things people would do or say simply to get the feeling of having a servant and not because they actually need a task done