Well there are things we know about it. When we go into a sleep state our conscious senses are physically put to rest and are likely not tapped into except in rare exceptions. We physically go into another level of consciousness and it seems that the subconscious holds a lot of information that we don't have the capacity to access when we are in a waking state. It isn't that our brain doesn't already have this information it is just that a sleep or trance state makes it easier to tap into.What is the explanation?