Is there some standard Mahayana doctrine about dreams and illusions?
How is the doctrine meant to be used -- assuming it's a view, how is it meant to be effective?
I ask because of this answer:
Consider how it feels to wake up from a dream and realize that all you felt during that dream was, “just a dream.” All the passion you felt while dreaming would dissipate upon waking up with the certain knowledge that it was “just a dream,” right?
Now, what if you knew you were “just dreaming” while you were dreaming? Like in a lucid dream? The passion and zeal would dissipate right then and there as you would know it all to be unreal.
I don't think I have the experiences of dreams, described above -- instead:
The feelings, the emotional content, of a dream -- how I feel towards a someone in a dream, or about the place or surroundings in dream -- is not very different from the emotional content of waking life: similar feelings whether I'm asleep or awake.
There are some childhood nightmares I remember -- of falling out of a tree, or being chased by a dinosaur -- I still remember the fear ... I probably am (or could be) still afraid of being a young child chased by a dinosaur, even though I know that was/is a dream.
When I know that I am dreaming -- e.g. because I'm with someone in my dream who I know has died in waking life -- the passion doesn't dissipate. The passion is part of the dream, part of the memory perhaps, part of the fabrication you might say, just as much as the person's form (appearance, voice, character, actions) is part of the dream.
The "lesson" I get from the experience isn't that passion and zeal dissipate -- instead the lesson is that experiences (e.g. views of people and relationships) are mind-made. I assume that to whatever extent they're mind-made in a dream, they're similarly mind-made in waking life.
The experience even leaves me doubting (because it's contradicted by experience) whether sankharas (if that's what dreams are) are really "impermanent" -- or perhaps they should be called "attachments" or I don't know.
In summary I don't get the impression that dreams are less real than waking life, I do get the impression that waking life is mind-made like a dream.
I'm not sure these are the right "lessons" to derive from the experience though -- or are they? -- since they seem to contradict the answer quoted above.
Inaccurate/approximate portrayals of the word illusion might imply: "everything is an illusion, nothing exists, nothing matters" -- I think that's a kind of nihilist wrong view according to the suttas: how about in Mahayana?
Another problem I have with "dreaming" as a characterisation of or analogy for waking life, is that I think I'm quite passive in a dream: i.e. things happen to me, things come out of nowhere, unpredictable. I fear that may be an unhealthy, unwise, unskillful attitude to have towards waking reality -- is one supposed to be, instead, active (not just reactive) and intentional? What does "awake" mean, in context?
I note that the above doesn't mention anatta -- which, to the extent that the above is a problem, may be part of the solution -- but maybe the above question makes some sense as-is.