A friend of mine told me he had a astral projection experience. Being a strict man of science this struck my curiosity. Though I do not believe in astral projection it made me wonder something, I came up with an interesting theory on why people may believe they had a astral projection experience, because the brain can do something very similar, due to the way it works.
The brain is a type of neural processor. However the way it works is very different from that of a computer. When it comes to optical senses (sight) the cells in the back of your eyes pick up patterns of light coming into your eye and capture it as raw data that they then send to your brain. The brain than encodes the data into a 2D image that it stores in short term memory. However when the brain recieves enough 2D images it is able to encode and merge them into a 3D image of the object or place of interest that it can store in long term memory. If a person grows up in an area and spends enough time their they can reach the point when their brain has mapped out a 3D image of every object from every point of view, producing a truly complete image of the area. This data becomes so detailed that in day dreams or REM sleep the brain can actually see the area from a completely different viewpoint and "predict" what it would look like with perfect acccuracy by using refence data that it already has on the area.