To sustain happiness, you must work towards self-mastery. It’s an inward journey that requires substantial spiritual growth. Choosing empowering thoughts over limiting ones should become your natural way of thinking. You must make it a habit to look on the bright side of things and let go of the past; to stop living in the future and appreciate where you are and what you have right now; to withdraw from comparisons and love everything in this world without condition. Embrace what is. Be happy.