From my days working retail:
First one was an outside of the store experience: I was working at a Michael's Arts & Crafts during high school and made a point to

before going in and on every break. I walked out to my car to pack a bowl and go to Wendy's. I took the cash out of my wallet and put it in the cupholder while I packed a bowl. In the middle of this some lady comes up to my car (my window is down) and starts trying to initiate a conversation and then goes "...oh you're smoking weed?". I try to cover it up real fast and she's all "No, I don't care. I honestly wish I was smoking right now" then proceeds to give me a sob story about how she ran out of gas and needs a few bucks to make it to the next station to fill up. Knowing this is the oldest fiend juug in the book, I say "sorry, don't have any cash on me." She goes "well how about you give me that cash in your cupholder so I don't have to go inside and tell your boss what you're doing out here?" Heated, I throw the money out the window, tell her to **** off, and drove off. Didn't even smoke or get food. Just drove around pissed about how bad I got got.

Same job. I had just gotten an offer as a prep cook working in a nursing home kitchen (same job from the Lorenzo story from the Crazy Stories From Your Job thread). I was restocking shelves one day and this burly looking dude was standing in front of the area I was stocking with his kid. I motioned to walk past the display and said "excuse me" as I did so, and he said "you mind not walking in front of us, you ******* dickhead." I could immediately tell from the tone that he was dead serious so I just blew up on the guy. Starting cursing him out, getting up in his face, almost to the point where we were gonna fight. Finally a customer came down the aisle and broke it up and pulled me aside. He had heard how the dude had spoken to me and how he carried on and was on my side. Told me it wasn't worth it and it's dangerous to provoke someone that crazy. He was able to cool me down and I explained to him that I had just gotten a much better job and was sick of the mistreatment. He was really understanding and sympathetic, so I went in the back and threw him a friends & family coupon so he got 50% off his entire purchase. The other dude stormed out of the store immediately. Never faced any repercussions.
Not retail, but worse. From my days working in healthcare:
Had a patient's son request that we shave his mom's pubes. No.
Had a patient's daughter try to convince me that the reason that her mom's heart failure is getting worse is because she has sodium in her diet at our facility. She told me at home she has her mom on a "zero sodium diet." I explain to her that it was literally impossible to have a diet with no sodium and asked if she meant a "no added sodium" diet. She tried to shoot me down and said "NO. I SAID A NO SODIUM DIET." I explained how sodium is a necessary electrolyte for just about all neurological functions and for cardiac conduction, but she wasn't having it. I asked her that if her mother had bloodwork done at while she was home what would she expect the serum sodium level to be and she quickly replied "ZERO." At this point I lost my patience and said "well that would mean your mom would be dead." She just said "well I disagree" and I replied "this isn't a democratic process." She only interacted with the other nurses after that exchange.
We also had a dude that was completely alert, independent in all activities of daily living, and had no issues with his bowels or bladder. Conveniently enough though, every night at midnight he'd "accidentally" **** himself. He'd ring his bell and specifically ask for certain female aides to come in (it was right at change of shift and he knew the night crew ladies that he had the hots for were just coming on). He would't tell anyone why, but the aides would come out saying what had happened. The pattern was quickly recognized, so we nipped it in the bud as quick as we could. Every time he would ring the bell, we would send the biggest dude in the room to answer it. The dude would say the girls are busy, but he could help him with whatever he needed. He would eventually just get flustered and walk himself into his bathroom to clean the **** off him. He cut that out real quick after that.
