I don't work retail (I'd end up with dementia) but I do see my fair share of morons around all the fine commercial outlets out there
Exhibit A: Lottery Assclowns: These are the type who think they're brilliant and witty when they ask the clerk to give them a "winning ticket" and get pissed off if they don't get it. Newsflash shithead; the clerk doesn't know which scratch & win tickets are winners, and nor does he/she know what the numbers in the upcoming lottery draw is. I'm sure if he/she did, it's safe to say they sure as hell wouldn't be working retail.
Case Study #2: Miss-da-point-o-da-expresslanus Moronus: Ok it's a simple concept. Express lanes at the supermarket are for 15 items OR LESS. So don't bog it down with your gazillion items, dickass.
Numero trois: Brat pack: Here's a bright idea, let's bring a load of screaming kids to the mall-- and bitch at them when they start to get tired and cranky or if they plainly act like kids after they spend all day walking (toddlers can't fucking be on their feet all day) and sitting there while mommy or daddy fingerpicks through a bunch of shit that has zero relevance to said kids. QUIT BRINGING YOUR FUCKING KIDS TO THE GOD DAMN MALL. No one wants to hear them scream and see some fuckstick nag at them. If you need something from the mall, get it on the way home from work.