I have always believed that sad and sorrowful times become more bearable if there is someone watching us undergoing such trying times. So, that is the reason why the lead actor in American beauty is so joyful even in such bad times because he is narrating his woes to someone, and that is why the heroes we see in the movies are heroes, simply because there are so many watching them. So, I feel an effective tool for reducing the sadness and sorrow in a person’s life is to have a journal or something, and probably that is the reason why Anne Frank kept a journal when she was kept in the attic of a house to protect her from the Nazis.
So, my point is :The event of observation from an external person makes a person less sorrowful.
Another point is, if a person wants to test if he is really happy, he should see if he feels happy when nobody is watching him , and if he indeeds feels so , then he is truly happy.