The whole of Mandu Kupanisha, indeed all of Advaita Vedanta is here. How is it here? What we normally think of ourselves is this one. Our vantage point of all of life is this one right now. And what about dreaming and deep sleep? We generally explain it away. You put on the gross equipment of the physical world and the same consciousness with gross name and forms. These are nothing but again I'll repeat you the one consciousness. This is easily understood in dreams. Not only as the waker, as your entire world which you experience.
Swami Sarvapriyananda teaches one of the shortest and most profound upanishads accompanied by Gaudapada's Karika. This lecture covers Mantra 5-6.