Last night, I read the news about a professor who wrote the paper 20 years ago. He did some research about asking people whether they were happy and he came up with the conclusion that happiness belonged to two kinds of people, they are the one who lived in peace and the other was who lived with great achievement. But 20 years later, he decided to revisit these people and he found that the conclusion about happiness he made before was wrong. Most people with great achievement felt not happy because they met setbacks. The professor came up with the new conclusion that the real happiness lies in the peaceful soul. This is the code of happiness.