You walk into the kitchen to grab a—wait, why did you come in here again? A new study suggests that your brain is not to blame for your confusion about what you're doing in a new room—the doorway is. The work is in the Quarterly Journal of Experimental Psychology. University of Notre Dame researchers had subjects perform memory tasks, such as remembering the colors of blocks in different boxes. The volunteers had to do the task after walking across a room, or after walking the same distance through a doorway into a second room. And they did much worse after going through the doorway. And you can't blame the new room: their memories still deteriorated if after passing through a series of doorways they wound up back in the original room. The researchers say that when you pass through a doorway, your mind compartmentalizes your actions into separate episodes. Having moved into a new episode, the brain archives the previous one, making it less available for access. It's as if you slam a mental door between what you knew and…what was I saying?