Ten years ago, when my wife and I went to pick up our little boy after school, sometimes he ran in front of us on our way back home. It took us fifteen minutes to reach home. He liked his class and teachers. Once he arrived home, he usually take out his little book from his bag and told us what he was taught in the school. He was counting his fingers one by one and said: “One ,two, three, four and five.” When he tired , he took off his shoes and socks , and showed up his toes. Then he stepped on sofa and wiggled his waist. These gesture showed that he wanted to play with us.