I have learned from experience that happiness is an acquired skill. Children are one of the greatest lessons in happiness, constantly challenging us to enjoy the moment, as the next one will not be the same. Gratitude is essential to happiness. Every time our children rush up to us and smile, we have something to be happy about; every time we get out of bed and can take a deep breath and go out for a walk, we have something to be happy about-that is the essence of a happy existence. Happiness is a muscle we must use, or it will wither away.