We know joy when we are happy to take from life what is given. When we experience the joy of the soul and higher states of consciousness, this joy is the essence of completion and fulfillment. There is nothing that can add to it or take away from it. Joy is our natural state.
The grosser consciousness depends heavily on particles of matter. The subtler consciousness is more independent -- it does not depend so much on the brain. Luminance, radiance, imminence -- the three states of subtle mind -- all of these disappear in the clear Light, the innermost consciousness.