It sounds like a horror movie, but it is actually survival. While you sleep, special brain cells begin a cleaning process, breaking down damaged connections and useless information from the day.

This keeps your thinking sharp and prevents mental clutter from piling up. Without this process, your brain would slowly drown in its own waste, becoming foggy and confused.

Scientists believe this is one reason poor sleep is linked to memory loss and bad moods. Dreams may simply be the side effect of deep internal repairs happening in the dark.

So when someone says sleep is a waste of time, they are wrong in the strangest way. Your brain is literally eating parts of itself to stay healthy and intelligent.