Many people have dreams and nightmares in their life. And people might say that something good will happen or its good or bad fortune. To see a familiar person in ghost, feeling like you falling into a dark pit of nothingness, and the fear of clown chasing after with a giant hammer. Or seeing a set of an place that was there then seeing it again days later. I wonder, if the human mind is continuing thinking after we are resting. Also, the brain can develop feeling in the dreams and nightmares, making a person to smile and able to touch, smell, and interact into the dream. Nightmare make a person to feel emotional pain. Then there is the non-dreamers, people that sleep all night without dreaming or nightmares. Its interesting, how we all work and have different imagination.