Your brain is the most important organ in your body. Without it, nothing else would work—and you wouldn’t be aware of it if it did. It’s the repository of memory, mind, and feeling; the conductor of the orchestra that’s your body; the seat of consciousness that is you. Every day this three pounds of “thinking meat” navigates you through the ordinary and extraordinary events of being human—from waking to sleep, and everything in between. It guides your body through motions of intricacy and delicacy, ranging from the most gross to the most subtle of movements, emotions, and thoughts; from unconsciousness to wide awake and even hyperawareness. It allows you to see the stars through a telescope and a molecule in a microscope—and using instruments the brain has created.