The Zen Tails First Book of Happiness is subtitled Happiness is Sharing. It shows the student characters sharing with each other and they are happy. Grizzel Bear is not sharing and he is alone and he is not happy. In the end he does decide to share and he then experiences happiness. Parents can use this story and relate it to their child's own experiences of sharing or not sharing. Inevitably a child who is not sharing it not happy.
Happiness is the natural condition. We never ask someone what is wrong when they are happy. Only when they are miserable do we offer our sympathy and enquire as to the reason. Size 15cm x 15cm