one of my favorite things I learned a few years back was the
"Doorway effect".* The answer to "Why do I forget things when I
go through a doorway?"* I always thought since then that there
is some significance in gaming and doors/portals/etc.* Well, I
found a great article about game design theory on the very
subject... and I love that it goes through the history of
gaming, from Zork on upwards.
http://www.gamasutra.com/view/feature/193943/what_lies_beyond_doorways_in_.php?print=1