This is why I was never drawn to MTB. Then again I celebrated by 60th birthday (almost 8 yrs ago) by racing my Ducati against a Porsche Carrera. Hit 140 mph and shut it down. I was pretty far ahead at that point. So, who am I to judge one's passion? In any event, do what you do until you lose the feeling for it. You won't get old doing things you love.