HA! I found my first gray hair at 18. I have had noticeable gray for 30 years. I have never dyed my hair. Fortunately gray hair on women is more than acceptable now- enough so that every time I get my hair cut I am not solicited for a dye job. That has not always been my experience. I adore my gray.
My mom has been gray since she was 18 or 19 as well. She's been dying it ever since and finally stopped for a little while. I told her not to dye it again; there's something very regal and beautiful about letting it go gray/white. Men aren't the only ones who can pull it off!
I had a few grey hairs at 18 and now that I'm almost 60 those wisdom highlights are starting to outnumber the color. I don't mind. I even checked to see if Clairol still had the dye to make your hair totally grey - nope, long gone from the shelf.~cryssT