Expounding on my own little stories:
I once did work where there was a requirement to sometimes be out of the office giving customers a ride to various places. One morning I was checking the daily activities and noticed the name 'David Brabham' on the daily schedule and so gave the number a call to organize things. Lo and behold, it was the man himself and we spent a good 30 minutes driving through the Berkshire countryside chewing the fat about all and sundry in the motorsport world. Down to earth guy, and when I told him about what I believed was the first Formula One race I watched, he called his wife and told her about this and that he had finished 6th in that race (among other things, which included a shopping list from Morrisons. Told you he was down to earth...).
A different second hand story involves my grandfather. Back in the 50's and 60's he was an engineering manager with BEA and BOAC before going on to look after operations in various cities around the world for BA. He always enjoyed telling me of the time he was in Lisbon, sometime around the late 50's I think. An aircraft was being loaded for departure back to London and he got a call about a piece of cargo and a rather irate owner. The owner was Stirling Moss, and the offending cargo was his car which had been placed in what I'll call section A of the hold. Stirling wanted the car to be placed in section B, except section B was directly over the emergency hatch for the landing gear (don't quote me on the inner workings of Viscounts and DeHavillands - I'm not an expert). This request was both dangerous and illegal.
Along comes Mr. Everett, grand overseer of BOAC's engineering in Lisbon, who explains to Moss why the car can't be placed in a position which would potentially endanger the flight. As he puts it, Moss was "calling me every name under the sun, explaining to me how incompetent I was". My grandfather wasn't really the type to get flustered or lash out, rather he would calmly listen and then do what he wanted anyway. And it was ever thus. The car was placed exactly where the airline decided it was going to be placed, and from that day forth whenever Moss appeared on TV my grandad would chuckle and call him an absolute fool.