Although it might seem incredible, the reason why we do not objectively perceive the internal worlds is due to our psychological conditioning. Likewise, what little we do experience of dreams is filtered or obscured by our own subjective perceptions. Even though we assume we are awake, in reality we are always dreaming, since our mechanical ways of reacting to daily life merely reflect our unconscious tendencies manifested in sleep.
The question becomes: what exactly are dreams? How do we become aware of them in the moment? What practices allow us to experience realities beyond the body? By transforming our consciousness in the vigil state, we expand our perceptual range and no longer travel unconsciously throughout the astral world.