The dream condition is unreal. When we discover this for ourselves within the dream, the immense power of this realization can eliminate obstacles related to conditioned vision. For this reason, dream practice is very important for liberating us from habits. We need this powerful assistance in particular because the emotional attachments, conditioning, and ego enhancement which compose our normal life have been strengthened over our many, many years.
In a real sense, all the visions that we see in our lifetime are life the images of a dream. If we examine them well, the big dream of life and the smaller dreams of one night are not very different. If we truly see the essential nature of both, we will find that there really is no difference between them. If we can finally liberate ourselves from the chains of emotions, attachments, and ego by this realization, we have the possibility of ultimately becoming enlightened.
--from Dream Yoga and the Practice of Natural Light by Chogyal Namkhai Norbu