Dreams are like variations themes of your life, though in your life you have chosen from those possible versions. The dream events are like physical one a good deal of the time. Your dream perception seem physical; you walk you eat, and perform other physical functions.
Events do not become physical unless certain requirements are met and certain codes activated. Experiences at pre dream level occur at their own intensities. The knowledge is translated into information that is broken down in the dream state into more specific data highly symbolized sitting individual requirements and run trough the body in a kind of ghostly trial fashion.
It is further processed into individual significances drives or intents which convert in into required codes that will then determine the nature of actualized walking events.
Data must be of particular kinds of intensity before they register as physical matter or are experienced as physical events. Part of this procession occurs in the dream state. And creativity play largely part in the preliminary process.