Happiness is not something one defines. It comes in a thousand myriad little ways. Sometimes it is the pleasure of the moment, or the knowledge you have people who love you around.
Happiness is natural for children, but must be built with patience by adults. It can easily be stolen, if we let it be. But in the end, happiness is what we all aspire to, for ourselves and for those we love. A few words about ths most important thing.