Kids with high pain tolerance

Do any of your kids have a really high tolerance of pain? Abby doesn't cry. She can fall and skin her knees on the pavement or bump her head it doesn't matter and she usually doesn't cry. Today, she was playing and had opened the door and it pulled her toe nail back halfway back and it was bleeding. The only way I knew it was when I saw her toe bleeding. I am talking about way in the quick and her toe nail is ripped up the middle. She never cried, but it made my stomach turn inside out. It looks so painful?. I was wondering if any of your kids are like this? And why? I don't want her to cry about everything, but if something hurts I wish she would let me know. Beth