Laughter, humor, a lighthearted sense of being - all of these are an important part of a well-balanced breakfast, er, life. Without humor, there is no hope. Without laughter, no love. And with a heavy heart, we live only a life of sadness and despair. Our ability to laugh at our foibles and laugh with our friends is a key indicator for predicting how readily we'll bounce back from difficulties and how well we'll handle the curveballs that life throws our way, and a quick smile is always the best defense in a situation that's hit a sour note.
In addition, medical studies have shown that indeed, laughter is the best medicine. Not only does it flood our brain with "feel good" hormones and exercise our body's core trunk muscles with spontaneous and deep contractions, but it noticeably and effectively raises our immune system's defenses in ways that are only now being fully explored - an effect which lasts considerably longer than the laughter that triggered it. Laughing lowers your blood pressure and exercises the heart. It relieves stress and helps generate an overall stability of well-being.
People with notably jovial attitudes are seen as friendlier and better adjusted, and people are drawn to them like flies to honey. Socialization with peers becomes smoother and more enjoyable, and people can't wait to rejoin and reestablish the acquaintance of those with a good sense of humor.
Of course, this does not include "humor" that hurts - biting sarcasm, "witty" putdowns, jokes made at the expense of others, mockery and other such imposters. It is doubtful that any of these recreate the same effects as true humor and lightheartedness, and I know for a fact that they attract far fewer friends.
Go on, laugh! It's good for you. Learn to bring laughter and joviality into your life and every step of the way will be filled with the warm embrace of good times spent with good friends in good health. Salut!