Now what's the difference between retired and retarded? The new job is staying in shape. My daily walk is some 8 km up and down over hilly terrain in temperatures from +37 to -30 C.

It's not the years that will sideline you. It's the onset of deterioration or a debilitating medical condition. Staying in shape may delay the inevitable - no guarantee.

Errare humanum est. What is an acceptable error rate - given that there's no such thing as a perfect flight? The worst error is the one you don't recognize.

Along with the faulty human component, Mother Nature or mechanical failure can hand you a nasty surprise (many of which are not covered by the training curriculum) at any moment. The more you fly, the more more you are exposed.