First, health is the secret of happiness (the key to happiness). Only a strong man can enjoy the pleasure of life.
Secondly, happiness consists in contentment. A man who is dissatisfied with his present condition is always in distress.
无疑的快乐是世界上最宝贵的东西。没有它，人生将是空虚的而且毫无意义的。如果你希望知道如何获得快乐，你须注意下面两点。
健康是快乐的要诀。唯有身体强壮的人才能享受人生的乐趣。
快乐在于知足。一个不满于现状的人终是处在痛苦之中。
