I don’t believe we need a formal definition of happiness. Most of us feel  and recognize it instantly when it occurs. Happiness can be felt through the realities of positive emotions. If we are  lucky it returns to us often through experiences of love, joy, contentment, gratitude and positive well being. These can result from present or past situations. Such memories, present or past, give us a sense of success and goodness. They allow us to feel meaningful and worthwhile as we carry on with our lives. They can also reinforce in us a sense of meaning or purpose. If you get a good husband  you’ll become happy. If you get a bad one you’ll become a philosopher.