If you are happy then you will think more clearly, be more productive, more creative, do better quality of work, enjoy your life more, make better decisions, focus on more meaningful tasks, improve the quality of your life and the lives of people around you.
You must have self awareness and know what makes you happy and then do that.
Think about a time in your life where you were happy and everything just comes easy. What were you doing? Who was there?
Soak in this feeling and let it engulf your body.