'51 Must Know Facts about Brain' is a lively and information-packed book to know every important fact about the human brain-the body's control centre. Know how neurons work, how the brain develops, how it controls movement and perceives the senses, what happens during sleep, and how language, learning, and memory are developed. The human brain is the command centre for the human nervous system. It receives signals from the body's sensory organs and outputs information to the muscles. Around 77% of your brain is just water and it stops growing when you are approximately 25, but that doesn't mean that you have reached your intellectual peak. The adult human brain weighs about 3 pounds (1,350g). It is about 2% of the total body weight and is the last part of your body to die.