Ladies, I once worked for an Air Force major who was balding. His boss was an Air Force colonel with gorgeous thick grey hair. He explained it to me one day. It seems that our hair follicles grow INSIDE our head as well as outside. But as you know, the roots can only go so far, because we have brains, and they'll get in the way. Well, according to my colonel, as those roots are growing deeper, if they dont' find anything to grab hold of, they fall out. But if they find something they can root in, they'll hang tight and change color to grey.
So those of you with grey hair should be rejoicing, according to my grey-haired colonel
(who had the utmost respect for my highly intelligent major, but couldn't resist teasing him)