You know, they say that dreams are real only as long as they last. Couldn't you say the same thing about life? There're people that are mapping the mind-body relationship, of dreams. They're called the oneironauts. They're the explorers of the dream-world.

They say it’s just about the two opposing states of consciousness which don't really oppose, at all. In the waking world, the neural system inhibits the activation of the vividness of memories. And this makes evolutionary sense. You'd be de-evolved if you had the perceptual image of a predator to be mistaken for the memory of one, and vice-versa; which is that if the memory of a predator conjured up a perceptual image, we would be running off to the bathroom every time we had a scary thought. There has to be a certain mechanism in your brain, which allow dreams to appear real, while preventing competition from other perceptual processes. This is why dreams are mistaken for reality. To the functional system of neural activity that creates our world, there is no difference between dreaming a perception and an action, and the actual waking perception and action.