In Tibetan Buddhism the way to enlightenment or Nirvana is spoken of as being a path on which one penetrates the illusory nature of waking consciousness, dreams and dreamless sleep. To do this with waking consciousness one must arrive at a state of awakening from ones usual 'dream' of, or response to, everyday life. In other words a radical shift occurs in how one sees life. Usually one takes all ones emotions, ones thoughts and physical sensations so personally, and as a sort of reality. Yet no thought is ever the thing it is about. We think of the future sometimes for instance and might go through agonies of worry. But the thoughts are not the events that follow. And when the events themselves arrive, we can respond to them in countless different ways. Therefore to take thoughts and emotions as if they were real in a stable sense is an illusion. Recognising this not as a philosophical concept but as an experience is like waking up.
http://www.dreamhawk.com/buddhism.htm
http://www.dreamhawk.com/buddhism.htm