My hair was white when I was a child and gradually turned brown as I became an adult. When it started graying in my early 40's I started getting highlights because you couldn't tell when there were roots and everything kind of blended together. I did that for about 18 years until I decided not to bother any more. Now my hair is nearly white and I keep getting it cut shorter and shorter.

But here's the mystery: all my life my hair has been super fine and very very straight. Now the back and top is kind of kinky curly and I can just mousse it a little, lift it with a brush a little, and let it air dry, then pick it out and it's good to go. What makes peoples hair suddenly decide to get curly?