When I worked in a supermarket, a customer was packing his shopping into one of the shop's distinctive bag-for-life bags, it still had the tag attached and looked brand new, still with the folds they have when they arrive from the warehouse.
I didn't see him pick it up from the end of the aisle so it was likely one he had bought previously but it was policy to check, so I asked 'just to check, that you've already purchased that bag haven't you?'
He went OFF at me. Shouted that I was an idiot, why would he try and steal a BAG, how dare I even ask, he was very rich, how pathetic I was, maybe I would stoop so low but he wouldn't, no wonder I was on a checkout in a supermarket, maybe if I wasn't so stupid I would have done better in life.
I just let him rant, and then suggested he take the tag off so it was clear (as some staff don't ask, if the tag is still attached they just put the code in to charge the customer). He went off again and demanded to see the manager, I called the manager over who confirmed it's policy that we have to check, and he suggested he removed the tag as well, customer called me a stupid woman and slunk off.
I might out myself here as I love telling this - I was working in the supermarket because I got bored over lockdown and was dying to get out, so I did a shift or two a week. Also my best friend was the store manager so it meant we could see each other, but I'm self employed, very lucky to be doing extremely well.
About 8 months after this encounter with the shitty customer, I needed some quotes for a £500k job. I shortlisted four companies and they all visited me at my property (I'm very lucky to live in a lovely home, lots of land etc) to cut to the chase, yes, one of the potential companies turned out to be HIM.
I recognised him immediately when he arrived at my home but he didn't recognise me at all. I treated him the same as I would with anyone, coffee, talk of the trade, what needed doing, timescales etc.
After his pitch, I walked him to his car, thanked him for his time, shook his hand, but then just before he got in his car, I said 'have you taken the tag off that bag-for-life yet?'
He looked really confused, sort of laughed but didn't get it, but then, and it was blissful to see, the penny dropped. He went white. He opened his mouth, closed it, and didn't say another word. He got in his car and left.
One of the best moments of my life I think. I can't begin to imagine how confused he must have been.
Needless to say he didn't get the job.