What's the average age of having gray hair? Do you have one?

Philippines
@wrangel15 (1444)
February 3, 2009 7:01pm CST
I just discovered yesterday that I have gray hair. I just pull it off my head this morning. I don't know how I got it but I think I am too young to have many of them. I only saw one gray hair but I guess the number will increase as it started growing already. Hoping it won't. My father had them during his thirties. My mother also so I'm expecting they will only come out on my thirties. Do you have gray hair? What do you think is the average age when people start having them?