From years ago...
I'd just made SM for the first time, so I got to stand in the (at the time) cool "I'm a frequent flyer now" check-in line at MCO. My flight has been cancelled.
Guy in front of me - on the same flight - is being rebooked by the TA and loudly states "I'm a Platinum Medallion on this airline and I demand you put me in first class!" TA: "I'm sorry sir, there are simply no seats available in first." PM asks for management, blah, blah blah. DYKWIA.
Next up: me. "Wow, that guy was really a jerk!" I say to the TA, "I hope you don't have to put up with guys like that too often". She replies that, unfortunately, all too often she does, but that it's simply part of the job. We chit-chat a bit more while she reroutes me - on the same route as the PM.
Then she says "Mr. [me], you know, I have one seat left in first on that flight, and since you've been so nice I'm going to give it to you!"
It would be my very first upgrade (or FC seat at all), ever.
It was so nice to see the PM skulk to his seat in the back while I enjoyed my Baileys and coffee. I learned a very valuable lesson that day...