On Friday, September 7, 2018 at 11:04:18 PM UTC-4, George Haeh wrote:
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.

Very good points. I would add that the biggest problem might be modern diet.. Meals full of starches and easy sugar that drive glucose levels of healthy people high followed by a crash. This keeps repeating all day long. Along with this roller coaster goes our concentration. Of course the roller coaster is not only with glucose level but also with hormones. Eat well without loading on starches, sugars and fruit juices and you will be able to perform much better. Very are very few people who can handle the modern diet, especially once they cross into their 40s. Treat yourself to a full fat cheese as a snack, nuts, proteins and other healthy snack and you will find your brain working like in your 20s, but that takes time.