Broken Leg

My Broken Leg
After a week of my leg hurting me so much (for no reason), I went to a doctor, and it came out that it was broken, the problem is that I don’t remember breaking it, or even hitting it with something, so he explained that this kind of fracture is called Stress Fracture, which is a result of overuse of the bone, it happens a lot to the athletes, specially tennis and Basketball players, and to the soldiers.
The thing is I’m not a soldier, and I don’t play Tennis nor Basketball, I hardly play any kind of sports …..
“Do you walk a lot?”, the doctor asked, “Yes”, I answered, “Oh, well that is the reason”. Walking is one of my hobbies, actually I love walking a lot, I don’t do it to lose weight, to be more precise, none of the people I know walk as much as me.Cat
Well, I guess this leads me to the question that I always hate, What is it with the human body? If you don’t walk or play sports, you would have lots of health problems, if you do, you would have this Stress Fracture thing. and getting me back to teeth, you brush them twice a day, and you end up having problems in sleeping from their pain, and looking at animals, My parents have lots of cats, and a couple of dogs, I don’t remember any of them ever brushed their teeth, also I don’t remember any of them having problems in their teeth too.
So would someone explain to me what is it with the human body?