Happened once on AA, a few times with CATHAY.

AA: Charles De Gaulle to SJC a few years ago. Me on award business class ticket. Husband on business paid ticket.

Very overbooked flight. Gate agent was spruiking to what looked like thirty people waiting to hope to get on.

Upgraded husband (exec plat) and then me from business to first. First was full. Sounded like they then upgraded senior FF from economy to bus before letting those waitlisters on.

Slept like a baby. First time for caviar.

Thudded back down to earth when alighted from plane at SJC in the middle of summer: no bridge. Picture walking down the steps onto the tarmac in the middle of a summer day, sweating, etc.