The vast inner space we find in meditation is very close to the inner zone of sleep. No thought, no feeling, lots of being-ness is very close to the dream state. Actually meditation brings our awareness to a vastness of lightness of being, an intimacy, presence, an endless peace. But this realm is very close to dream state because for most people our awareness is literally tired, holding so much stuff, detail, stress of modern life. The heaviness we carry in our mental life drags us down. This drag downward is not into deeper meditation often but sleep.