You just had the wildest dream. You were flying over your school, your math teacher was a penguin, and you could speak Japanese. You sit up in bed to tell someone about it. And... it's gone. Five seconds ago, the whole thing was and clear. Now your mind is completely . You cannot even remember if the penguin could talk.
Here is what might surprise you. You dream every night. Everyone does, even people who say they never dream. Your brain goes through several of sleep, and dreaming happens during the deepest one. Most people have four or five dreams a night. Almost none of them in your memory by morning.
So why does this happen? Your brain is not being lazy. During sleep, a in the brain drops to a very low level. This substance normally the brain to new memories. Without it, the dreams you see at night never get saved. Your brain treats them like temporary files it does not need.
The moment you open your eyes, the brain a rush of that substance and starts recording again. But your dreams are already . Scientists say you have about five minutes. After that, the details disappear, like writing on a foggy mirror. The window is . If you do not grab the memory right away, it is gone for good.
Why would the brain throw away its own dreams? One is that dreaming helps sort . During the night, the brain feelings from the day with random images. Once the sorting is done, those images are no longer useful. Blind people dream too, by the way. Their dreams are built from sounds and touch rather than pictures.
Want to remember a dream? Keep a notebook next to your bed. The second you become , before you even check your phone, write down whatever you can. Even a few words will do. Your brain is already working to erase the dream, so it while you still can.
