The physical act of walking through a doorway is the reason why you sometimes walk into a room and completely forget what you were doing. Going through a door signifies the beginning or end of something, so it creates an ‘event boundary’ within your mind. Every time you pass through a doorway, your brain is filing away the thoughts you had in your previous location to make room for a new group of memories in the next.
“There are books that one reads over and over again, books that become part of the furniture of one’s mind and alter one’s whole attitude to life.”