I remember walking into a Yin Yoga class after not having had any yoga or exercise for that matter for a long time and being the WORST. And, there were women in the studio who were completely grey AND they were flexible. Much older than I was yet much more flexible. So that was a lesson in humility. But now the way I look at it as follows: if I keep at it, I will eventually be as flexible when I am as old as those women. I may not choose to wear my hair grey, but I would be flexible.