As humans we are forever searching for happiness. Yet happiness is that elusive thing where the more you search for it, the less you will find it. Happiness is a result of gratefulness for what you do have and not for what you would like to have.
A good example is that many people expect they will be happy if they win the lottery yet strangely enough most people who do win the lottery tend to discover greater unhappiness and long for the days when they were really happy with what they had. Often the money does not last and things cannot return to what they were.
So the lesson is in learning to be happy with the things you do have whether it be health, a roof over your head or even your child throwing a smile your way!