The theory that every exit you make is an entrance somewhere else.
Grasshopper: Dad, do you mean that if I hop through this door; not only am I exiting this room, I am entering this other room at the same time.
Dad grasshopper: Yes grasshopper, you are getting wise young one. Actually there is no such thing as a singular exit or entrance. They are one and the same thing.
Dad grasshopper: Don't think about exitheory too much, your prothorax will explode.