Happiness is a feeling, let a person produce joy, peace, contentment, happy feeling.I think, one of basic needs, should be in contented attitude,as for self- realization must maintain the spirit of insatiable.So easy in comparison to to social, physical, , social, environmental aspects of balance, while this balance to bring people a sense of . happiness. Any of certain aspects of the extreme pursuit will destroy the balance, and the lost happiness. Use this standard to control around you, you will see different people's different life, different life experience. The feeling of happiness is to arise spontaneously, happiness comes from the life of the current . state of equilibrium.
This is what I think.