The answer is pretty simple. They're so hard to kill, no matter how hard you try. Back in the 60s, I bought five F's, plain prism, new for about half price from a Tokyo dealer. I addd a couple more used and none of them ever quit. I had motors on three. I couldn't afford camera down time and frequently worked with three F's and an SP -- you had to be there. That was news. But commercial work sometimes got complicated with multiple emulsions and limited time. I dropped them, bent the prisms, cracked them and ran them to death with the motors. One of of the used bodies had been used so much our repair service said it wasn't worth repairing, but the speeds were on. They were all still working in 1980 (I had left the trade) when a burglar took them and a dozen others, including a really sweet Rollei 2.8E2 and several LF lenses I'd held on to.
I now have one LN F which is of the same vintage as mine, a gift from my father who had put in an order through me for it, along with a set of LN lenses that mirrored my taste at the time. Any time I pick it up the speeds are right, it's clean and it's never seen a CLA. I have a couple of OLYs like that from 1980.
Maybe you're just living right.