A Hairy ordeal

Well, this might be TMI, but at age 52, there is rarely a need to shave the legs because well, they're just not hairy anymore like they were in my younger years. However, when I was drying off from my shower today, I noticed that the injured upper shin area of my right leg (injured from the Labor Day bike crash) has lovely thatch of hair that is out of character. I'm wondering how the injury induced this phenomenon, because that hair was not growing there before. It's just the weirdest thing!