On of my grandfathers was a mechanic for NASA (Lewis Research Cewnter), but about the time I was hanging around him he was retiring, and I didn't get to learn much. It was kind of interesting wandering around the lab and seeing open containers of liquid nitrogen just sitting on the floor boiling away. I did see him turn a bushing once to repair a washing machine. Most of the time he was playing on his small farm.
My other grandfather was a pre-WWII era machinist. Born before the turn of the last century. He died before I really got to know him, but I remember being out in one of his quanset huts were he stored tools and equipment with him showing off boxes of tools he bought from stores going out of business or at auction. At that age I couldn't understand why anybody needed a whole box of tubing cutters, but as I've gotten older I've learned most tools are like fish hooks and rope. You can never have to much. I do have some of his tools. My dad bought many of his machinist tools from him before he passed away, and a few years ago he gave me the lot as Christmas present. At first I just piddled with a lot of it, but I've since found a few tools in there that I use nearly every day, and most of it that has been used occasionally.