Job: cashier. Not my current job, but definitely the one that racked up the most irritating quotes.

Customer: "Now, don't you try to double scan my items. I'm watching you."

I heard this one constantly when I was a cashier at a grocery store. At first I assumed that they were kidding. After all, it's such a stupid accusation to make. It was only after about 100 elderly people had said it while staring daggers at me that I realized they weren't kidding.

I assume there must have been a news report in the 1960s about store clerks charging you twice for an item and then taking the extra cash, and a certain kind of person had been paranoid about it ever since. Except this wasn't in the 1960s, it was the 2010s, and such a scam couldn't even work anymore. The cash register isn't just a lockbox like it was in the 60s, it's a computer and it knows exactly how much money should be in it. And if it has less than that in it when your shift ends, you're screwed.

Plus, you're paying with a credit card, Gertrude, how am I supposed to steal your shit when you're paying with a credit card?

I think the thing that made it so irritating was the fact that they are willing to whip out this assertive, domineering attitude at you based on information that hasn't been true for about forty freaking years. They have a mistrust of other people because they don't know how the world works anymore, yet they think they've outsmarted you.