Lama Ole’s answer:
If we hold on to the moment where we know, “this is a dream,” and then expand this feeling more and more, we can become fully enlightened this way.
We have yogis who got enlightened while dreaming and in deep sleep—maybe not so many, but it has happened. If one recognizes the moment of dreaming and extends it into the day, this can provide great protection and keep a lot of disturbing emotions away.