To laugh is to feel good. Laughing fuels the endorphins, which is a natural drug that makes you feel good and uplifts you. Try to laugh everyday, and try not to sweat the small stuff. Here are some quotes related to laughter.
"We don't laugh because we're happy, we're happy because we laugh."
-- William James
"Laughter is like the human body wagging its tail."
-- Anne Wilson Schaef