We are all aware of gravitational force. We all know that, if we throw a ball, it will certainly come back to us. We all might have noticed that if we smile at someone, the other person smiles back to us. It is like reflex action. In the same way if we are always in a happy mood or totally in harmony with happiness, we will attract good things in our life from the universe. So, keep smiling and why not attract whatever we want in our life?