WHY ARE SOME HAIRS WHITE?

One day, a little girl was sitting and watching her mother do the
dishes at the kitchen sink. She suddenly noticed that her mother
had several strands of white hair sticking-out but in contrast to
her brunette hair. She looked at her mother and inquisitively asked,
"Why are some of your hairs white, Mom?" Her mother replied, "Well,
every time that a little girl does something wrong and makes her
mommy cry or makes her unhappy, one of her hairs turns white."

The little girl thought about this revelation for a while and said:

"You must have really pissed off Grandma."