My first FC trip was back in 1979. I was on my way from Stockholm to Melbourne via I don't know where anymore. I had just spent my compulsory 24 hours stopover in Singapore (life's tough sometimes) and got to the airport.
I knew I had a problem with my ticket even before I left, I was waitlisted on Qantas from Singapore to Sydney, but the travel agent advised me to check at the aiport. I did, and of course coach was full. I started with the old "but I have to be in Melbourne for an important meeting tomorrow, that's the only purpose of my trip" (which was true - honestly). The agent wouldn't/couldn't do a thing for me, but after some more discussion the supervisor came over and asked what the problem was. After repeating my situation, he took the ticket and left. He was back with an FC boarding pass and wished me a pleasant flight!
Oh yes, it was pleasant! Lobster and champagne for dinner is all I remember of the meals. I watched the sunrise over the Outback from the upstairs lounge and was politely called back downstairs by the purser when it was time to land.
After that it was difficult to go back to coach, but fortunately PanAm had some pretty good upgrade policies in the 80's and 90's so most of my trans-atalantic and US transcon lights were in first.
/Pete