I wonder...

There is a woman in Gainesville that is a compulsive walker. She is rail thin. As far as I could tell, she walks every day. I have no idea how far she walks but she seems to have a circuit - not around town, but around the entire city. No matter how hot or how cold, she walks. She always wears a hat, long pants, a long sleeved shirt and a jacket. I often wondered how such a habit, if you can call it that, begins. Does it come about gradually? Or is it more acute? One day you're walking to your car and you just keep going and going and going?