I sense the physical world on a different plane than the spiritual world. I also agree with Mark Lapierre that its a matter of perspective.
People have expressed difficulty distinguishing between their imaginary vision and conscious awareness at different levels. Experiences in astral travel can help people learn to discern differently than they had previously. I wrote a post about some of the incentives to deepen experience in astral:
7 incentives to learn astral projection - Dream Builders - Dream Builders: Empower more than Motivation & Goal -setting