Happiness is like a pebble dropped into a pool to set in motion an ever-widening circle of ripples. As Stevenson has said, being happy is a duty.
There is no exact definition of the word “happiness”. Happy people are happy for all sorts of reasons. The key is not wealth or physical well-being, since we find beggars, invalids and so-called failures, who are extremely happy.“快乐”这个词没有确切的定义，快乐的人快乐的理由多种多样?？炖值墓丶⒉皇遣聘换蛏硖褰】?，因为我们发现有些乞丐、残疾人和所谓的失败者也都非?？炖?。
Being happy is a sort of unexpected dividend. But staying happy is an accomplishment, a triumph of soul and character. It is not selfish to strive for it. It is, indeed, a duty to ourselves and others.
Being unhappy is like an infectious disease. It causes people to shrink away from the sufferer. He soon finds himself alone, miserable and embittered. There is, however, a cure so simple as to seem, at first glance, ridiculous; if you don’t feel happy, pretend to be!