Yes I do, I worked retail in a large pharmacy chain when I was sixteen for summer job, some of the people you have deal with are just complete and utter morons. I'd be asked questions like 'Why is this so expensive or why is this cheaper in another shop' and I'd just stand there looking at them, thinking to myself does it look like I have a say in the prices you cabbage.
Some people aswell just love opening dressings or packets right in front of you which are supposed to be kept sterile etc to 'see how big they are' and I'd be like >.< YOU CANT DO THAT!!!!! Eventually you will get through to people by saying by saying would you buy a box of sterile dressings if it has been opened and handled???
I remember one particular woman was looking for batteries for hearing aids one day, and she asked me 'Will these fit the hearing aids that my son/daughter owns (cant remember who they were for)' and I replied what with 'Do you have the packet of batteries on you or the hearing aid on you and we can have a look' To which she said she didnt and I said 'How am I supposed to guess when there are about 8 different sizes', she was there for about 10 minutes asking which ones would fit.... I dont think I've ever met anybody like her, she litterally would not listen to a word I was saying to her and she was insisting that I should know what would fit the hearing aid.
If I can help it I'm never, ever going to work a job where I have to serve the general public with a smile on my face ever again. True not everyone is an ass and most people are a pleasure to deal with, but it only takes one person to completely cock up your day.