"The Doors of Perception": how does it work?

[carwashguy]

I was reading Keelin's Diary from Lucid Dream Camp, which documents what went on in Laberge's lucid dream workshop back in '95. This particular paragraph piqued my interest: The Doors of Perception required that we touch each doorframe as we passed through. The concept behind this exercise, is to increase awareness and to begin a new habit which can be carried over into dreams. Each time, each doorway. So simple. Yet within minutes, I discovered what a formidable challenge this can be. He doesn't say exactly how this is supposed to help one to become lucid in a dream. Does anyone know? My immediate suspicion is that maybe your hand will go through the door frame in a dream (like the finger-through-palm check). Then again, perhaps it has something to do with how dream scenes tend to change upon going through a doorway. Maybe the fact that you're exercising this dream-related habit when the dream scene changes is enough to alert someone of what just happened. Maybe it's simply a reminder to question whether you're dreaming every time you do it, or maybe it's a combination. Any ideas? I think I might try this out.