Five Surprising Facts You Didn’t Know

Five facts you probably didn't know. One: Did you know your brain can't feel pain?

That's why surgeons can operate on it while you're awake. Headaches don't come from the brain

itself. They come from the tissues around it. Two: Did you know octopuses have three

hearts? Two of them stop beating when they swim so the octopus can conserve energy

while moving. Three: Did you know you've never seen your real face? Mirrors flip it

and photos capture angles you're not used to. Everyone else sees the version you

never do. Four: Did you know space is completely silent? Sound needs air

to travel, so those massive explosions in space movies are fake. Five: Did you know