I was a cashier at A&P (its a supermarket) last summer and this summer. Man, I really learned a lot about dealing with people.
One time this woman bought about $150 worth of groceries, then took out some type of card. I asked her, "Credit or Debit?" and she goes "Whats the difference between credit and debit?" I sort of stared at her for about 9 seconds until I said, "...excuse me?" "What does credit and debit mean?" "Umm... Debit is just taking money out of your own account while credit is charging it now and paying for it later." "Oh okay... debit."
Oh, and I really can't stand the customers who have a ton of stuff and while I'm scanning it and placing it on the conveyer belt and letting it all build up at the end of the register (where, I might add, there are TWO bagging racks set up specificially so that the customer can bag their own groceries) while they sit there and watch the screen like they're gonna get charged an extra grand if they dont watch every price appear on the monitor.
It pisses me off when I check fruit for a PLU number and they see me looking at the fruit and tell me a price for it. I don't know if their price is right or wrong but either way I have to enter it by its code, not the damn price per pound.
Also, when I turn out my light on my register, that means that the register is CLOSED. I can't stand when people pull their carts halfway into the register aisle and look at me and ask if I'm open. Oh yes, I just thought it'd be funny to turn out the light and start putting everything away. And since we're on the subject of register misconceptions, the express lane means 15 items or less. When you come up to it with a full cart of stuff, I have to tell you that I'm express and you have to go to a regular register. I don't care if they have lines and the express is open. If I take you, then if someone with under 15 items comes, not only is it not fair to them, but they can complain and I will get yelled at for letting you on the express lane, so shut up and follow the rules of the supermarket.