White hair
One day, a little girl is sitting and watching her mother do the dishes at the kitchen sink. She suddenly notices that her mother has several strands of white hair sticking out in contrast to her brunette hair. She looks at her mother and inquisitively asks, "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."