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.
Fact of the Day
When you can’t sleep on your first night in a new place, your brain is trying to protect you. Many animals sleep with only half their brain, while the other half stays alert to possible dangers. It’s called the ‘first night effect’ in humans, because our bodies put us in a strange, half-asleep/half-awake state the first time we sleep in an unfamiliar environment.