People who suffer from this disorder flail, sleepwalk, etc., and can be a danger to themselves or others. Such people do not leave their bodies, but they often leave their beds during sleep. Another curious quality of brain activity during dreaming is that almost all dreams are forgotten. Dream amnesia is the norm. This is not due to anything paranormal or supernatural, but to weak encoding.
Memory depends upon encoding the data of experience.
Encoding depends upon connections in parts of the brain, which in turn depend upon connections in experience. An event with a strong emotional component is more likely to be remembered than one with no emotional component because emotional memories are recorded in one part of the brain while visual components are recorded in another. Neural connections link them. We are likely to remember dreams if we wake shortly after they occur. Even so, if we do not encode the dream by making some effort to remember it, we are likely to forget it.