I'll never forget my first time I just landed my first decent job in 1979 and was flying UA SFO-ATL-PHL. I was a flying Noob. Some UA union had a strike deadline on the day I was scheduled to fly in the middle of my first flight segment. I asked my new boss if I should be rebooked on a different airline. He said not to worry (he was like that). He said hopefully they wouldn't strike that day and if they did then the company travel agent would take care of me.

I got on my SFO-ATL flight and enjoyed it thoroughly on the DC-8 listening to the pilot chatter on the seat headset. When I arrived in ATL I immediately discovered that the UA union had gone on strike and all UA flights were grounded. I called the (Fortune 100) company travel agent and found out that they had proactively rebooked me while I was in the air for standby on an Eastern Airlines flight from ATL-PHL. I got to the Eastern gate and it was pandemonium, people everywhere. They boarded the confirmed passengers and there was still a huge mass waiting to clear standby. I was called as #1 on the standby list and they Op-Uped me to First Class! How sweet it is! That was back in the day when domestic First was pretty nice. I think I took the only remaining FC seat. All the other standbys went back to coach.