Was flying WT on 777. The captain started chatting with me (this captain clearly likes doing that). He told me about a company he is a director in (I must have told him that I develop electric trucks). I was able to name the company and had recently visited it (near EDI).
He upgraded me to CW...
On a AA (well US during the transition) I didn't sit in my assigned exit as there was 3 seats across empty near by. The guy who was next to me in the exit moved to my window seat. Shortly after takeoff he was moved to business (I assumed he was staff)
A little later I chatted with the FA on my free drink (EXP on AA privilege) she asked my name, and realized that it was me that was meant to be upgraded. She asked the other guy if he was mr seaskybound and he said yes (but it was not intentional mistake, noise of aircraft etc). They let him finish the meal and we swapped (all in good mode)
It was the business purser that saw there was 1 exp on generally empty flight that organised this in the first place