I found my first grey hair 6 days after my 21st birthday. I pulled it out and taped it to the bathroom mirror. It was the shiny, sparkly kind, like my grandmother got, which I thought was beautiful.When you no longer care about how many grey hairs you have (earned) and no longer pluck them out.
It grew back. I pulled it out again. It did not grow back, and I've never pulled out another grey hair. And if their are all as sparkly as the first one, like grandma's, I'll consider myself blessed.