Enough rain to make your hair curl

I got caught in the rain today. For the most part I looked like a drowned rat, but those little pieces of hair around my face - you know, the first ones to fall down as a hairdo loses structural integrity - seem to be curling in a quite graceful and attractive manner.

This has literally never happened before in my life. I wonder why? My hair has never been one to respond to humidity in any way except by looking limp and flat. If getting wet in the rain and then air-drying causes curls, then, logically, showering and air-drying, like I do every day, should also cause curls. But it doesn't! Maybe there's hair perm chemicals in the rain?