dreaming

Dreaming is the experience of seeing, hearing, feeling, and living through little stories inside your own head while you are asleep. Even though your eyes are shut and your body is still, your brain spins up whole scenes — places, people, and events that feel real in the moment, often strange or jumbled, and usually starring you. It is a bit like watching a movie that your own mind is writing, directing, and screening for an audience of one, all without any input from the outside world.

Dreams can pop up at many points in sleep, but the most vivid, story-like ones tend to come during a stage called REM sleep — short for rapid eye movement, named because your eyes dart around behind closed lids. In this stage the brain is almost as active as when you are awake, yet the body's muscles are temporarily switched off so you don't act out the action. Scientists are still debating what dreaming is for: leading ideas include helping the brain sort and store memories, practicing how to handle emotions and fears, or simply being a side effect of a busy sleeping brain stitching random signals into a story. Whatever the reason, almost everyone dreams every night, even people who rarely remember it by morning.