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