In terms of Life, Happiness means that your life energies are happening in a more exuberant way than it normally happens. Depression means your life energy has become low & staid.
Additional information/ Source: https://www.youtube.com/watch?v=BA_t1XyZmNI
The science of yoga is just this: learning to harness and direct your energies in the right way so that 'who you are' finds its ultimate expression. If you do not allow this energy which you call as life to find its expression, it naturally tries to find its way out in violent waysExpand ⇕
External pleasantness needs cooperation from many people. It’s not just yours. There are other stakeholders who may want to make it nasty for you. It needs many people’s cooperation but inner pleasantness is one hundred percent yours. But why have you not strived for it?Expand ⇕
If every moment of your life, no matter what the nature of your work or your life situations, you can remain playful and exuberant, that means you are liberatedExpand ⇕
The quality of your life does not depend on your clothes, car, or home, but on how peaceful and joyful you areExpand ⇕
The greatest fulfillment in life is to do something which is much larger than yourself.Expand ⇕