I had a 172 at KAPC long ago. Joe Montana had a Malibu. One day, he had a busted AN4 bolt in his nose gear. It was a Sunday afternoon, no FBO shop open. I got my jacks, lifted the gear, swapped out the bolt, shook his hand and sent him on his way. Never once acknowledged, "who he was." When I was done, I shook his hand and said, "Howdy, I'm George (not my real name, and not the name I told him), he smiled, shook and said, hi, I'm Joe and that's my wife Jennifer." I went inside the admin building to wash my hands in the washroom, and he followed me in. He bought me dinner, topped off my fuel tanks (I used autogas at the time so he just gave me $20 for gas, which bought almost 20 gallons at the time), he and Jennifer got in the Malibu and flew away. Never spoke to him again, but I was a good boy scout for the day. Always did almost all of my own maintenance. Rebuilt my own engine. Supervised, of course.