How doorways destroy memory
In one common but mysterious short-term memory failure, people find themselves in a room, without remembering why they ended up there. Researchers say, in these circumstances, the doorway may be to blame. The very act of walking through a doorway may hint to the brain that a new scene has started and it should store prior memories away, thereby causing strange memory lapses. [Top 10 Mysteries of the Mind ]
"Entering or exiting through a doorway serves as an 'event boundary' in the mind, which separates episodes of activity and files them away," Gabriel Radvansky, a psychologist at the University of Notre Dame, told Live Science in a 2011 interview. "Recalling the decision or activity that was made in a different room is difficult because it has been compartmentalized."
But still, mental event-boundaries are useful, because they help us organize our mental timelines and remember not just where, but when a particular event happened.