Color?

I realized today that I had a box of brown hair dye stashed under my sink.

I was agonizing over how desperately in need of a re-dye my hair is (probably have 2-inch roots by now) and surprised by how dark my roots are at present, and I started thinking, huh, maybe I could just go darker again.

This was, of course, met with much resistance on Facebook by my parents, and mixed opinions from friends.

I'm fairly certain I'm just going to go for it. I've been a brunette before, and I wouldn't mind being one again. If it doesn't turn out great, I can just get it dyed back to blonde by someone professional when I get back home in 2 and a half weeks.

Why not?