So, this topic looks like to turn out to the famous male contest: who has the largest D...

We all know that there are always exceptional guys in that contest. And we also know that this small group is not decisive for the general question.

In fact in general it has to do with a lot of luck with regard to your body and mind.
Yes, I know, training and self-discipline play a big role. And for that you have to give credit to these old fogyes.
But if you have injuries or a fading mind it overcomes you when you are getting older. There's not much you can do.

The only way you have to slow down the degradation is to hang-on and postpone the decision to quit.