Let me start by telling you a story. There was a man who was afraid of his own shadow. Every day he used to walk fast and even run just to get away from his shadow. Once he decided to run so fast that the shadow will leave him, instead he ran so fast that he died of a heart attack. Only if he would have waited in the same spot for a while, the sun would have come right above him and the shadow would disappear.
In the same way if we just sit on a given emotion and think about it for a while, it disappears. Try this, the next time you get angry on anything, later sit back and think and rethink as to what exactly made you angry, the more you think on it, the more will you realize that getting angry was unnecessary. Same thing goes for sadness. If you sit on it for a while and try to analyze it, you will realize that you were sad or angry for a silly reason and quickly life will seem to bounce back.