I started going gray in junior high. It was just a few strands in which I took pride thinking it showed how stressed out and serious I was. Fast forwarded 15 years and I hate the gray I have all over, but mostly right in the front.
Now, covering grays is no joke. They don't absorb the color and don't hold it for too long, either. I started coloring it with liquid henna that Whole Foods and Mother's Market carry. It was fine, but a pain in the ass. I would have to shampoo my hair and let it air dry for a bit. (Side note: I have giant, Diane Ross/Slash hair. I mean there's a lot of it, it's curly, and it's huge. Wider than my shoulders huge. My nickname in junior high was actually Slash.) I'd do my best to saturate my hair, put a plastic bag on my head, and let it sit for hours while I cleaned the house. I did this every other Sunday. About a year ago, I got so tired of the effort and time suck, so I stopped and decided to let my gray streaks fly.