Recall that the ancient method of loci involves going through doors as part of remember things.
Is this a disadvantage of it compensated for by its advantages? Is this a method it uses to reset the mind and make it easier to recall other things?
My guess would be that we associate memories (especially memories of objects) with specific locations and can remember them better when we're in those locations. One, easily testable, prediction of this theory is that returning to the original room will make the memory more easily accessible.
http://www.springerlink.com/content/m6lq80675m22232h/
There's probably some deep implications to this I'm not qualified to plumb. But next time I'm concentrating on something, and need to get up from the computer and walk around a bit, I'm going to try avoiding doorways.