Can somebody please explain this to me?

I have a full head of hair. Not a single ounce of baldness. Yet, somehow, this has happened.

 No, I am not wearing socks or ankle weights.
Here it is closer up:
News alert: it’s physically impossible to take a picture of your own legs head on. I know because I tried. Then called Wife over to do it for me.
Yes, my leg-hair doesn’t start until about half-way up my lower leg. 
And yes, my flesh is blinding.

I have no idea what this means, but it pretty much looks like I had a pair of white socks tattooed to my ankles. Especially when I’m not tan. Like right now.

Theories:

I wore socks that were too abrasive as at some point in my youth.

A leprechaun shaved my ankles in my sleep using a magic razor.

I am simply going bald starting from the bottom up instead of the top down.

I have cancer.*

I am a leper.

I am Benjamin Button.

Which do you think it is? Or perhaps you have another idea as to what might be happening here?

Also: Rogaine? Thoughts?

*I’m sure there must be a cancer that involves ankle baldness. But even if there isn’t one, I think it’s pretty clear that my “perma-socks” are most likely insidious and life-threatening.