There's an old Arabic joke, about an old man with two wives: one old and one young. He alternated nights, between them. While he slept, the young pulled out all of his gray hairs and the old pulled out all of the black ones. He wound up bald!
did you know that sometimes you get grey hairs just from being very upset or under alot of pressure? thats how I got mine... then they were gone (and Im exactly your age!).