They say that "Laughter is the best medicine". I believe it's true. Medically speaking, it forces air through your lungs and relieves stress that may be building up. When you laugh, it gets others laughing with you. It is very contagious.
I certainly need to laugh more than I do. I shoot for about once a day. For some reason, I go into this hysterical laugh about once a day, usually in my daughter's room. I swear she must keep some laughing gas in there somewhere. She kinda just shakes her head, which gets me laughing even more. It's quite fun and if you see me laugh that hard, well... it may send you running the other way. But it sure clears out the stress for a bit.
Everyone should try it at least once a day. It's good for your heath!