One day a little girl was watching her mother washing dishes in the kitchen. She suddenly noticed that her mother had several strands of white hair in contrast to her brown hair. She inquisitively asked, "Why are some of your hairs white, Mum?" Her mother replied, "Well, every time you do something wrong and make me unhappy or cry, one of my hairs turn white." The little girl thought about this revelation for a while and then asked, "Mummy, how come ALL of grandma's hairs are white?"