So it has been said by Tochihuitzin,
so it has been said by Coyolchiuhqui:
We come here only to sleep,
we come here only to dream;
it is not true, it is not true
that we come to live on earth.
ANON. AZTEC, 16th century
(adapted by David Damrosch from the translation of John Bierhorst, Cantares Mexicanos 18:39)
(I found this quoted by Dave in his epic Cibola)
La vida es sueño. We don't often enough pay attention to what it means that we can dream. That we can manufacture out of our minds an entire experiential world. When we drop out of the dream world into another experiential world, which we call waking up, we say that oh, this time we are in the real world. This one is more stable than the dream worlds -- we seem to return to it over and over. Or does it only appear so? The dream worlds appear stable when we're in them, too. If we can manufacture a present, we can certainly manufacture a past -- anyone who has researched memory will tell you that we do so, all the time. We do not have much foundation for our confidence that waking life is more real than dream life. We remember our dreams as scattered, inconsistent, with abrupt unexplained shifts of scene; but really we remember waking life the same way. We just have confidence that if we looked, we could find the unity and consistency. We share waking reality with others -- but then while we're in out dreams we appear to share the dream reality with others, too.
I have no interest in arguing that dreams are real or that waking life is unreal. That seems to me to completely miss the point. The point is, that creatures who are capable of creating realities for themselves should have some healthy skepticism about any reality they find themselves in.