We spend a third of our life sleeping. No matter what we do, however virtuous or non-virtuous our activities, whether we are murderers or saints, monks or libertines, every day ends the same. We shut our eyes and dissolve into darkness. We do so fearlessly, even as, everything we know about “me” disappears. After a brief period, images arise and our sense of self arises with them. We exist again in the apparently limitless world of dream. Every night we participate in these most profound mysteries, moving from one dimension of experience to another, losing our sense of self and finding it again, and yet we take it all for granted. We wake in the morning and continue in the “real” life, but in a sense we are still asleep and dreaming.

The Tibetan Yogas of Dream and Sleep - Tenzin Wangyal Rinpoche