We've all had the frustrating experience of going into another room to get something and then realizing... we've totally forgotten why we're there. What's happening, say scientists from Notre Dame University, is that the act of passing through the doorway serves as a cue
(an "event model" in science-speak) to your brain, telling it that it's finished with the immediate task and to move on to something else, freeing up space and energy for new memories. You can take advantage of this mechanism in order to help you "forget" more strategically: If you find yourself getting worked up about something while you're preparing dinner, stop and exit the room. And if you happen to have an open-plan layout, keep on walking right out the front door (just come back in before the water boils and the pot overflows).