Mind and brain are not the same. The brain is an organ that is in your skull. You have 2 nervous systems. One you control, the other called the Limbic system, controls the inner organs so you don't have to think, lungs breathe, heart beat now etc. Your Mind doesn't live in your skull. Mind is not an internal organ. If you cannot control your mind, you need practice and self discipline. When the Sensei asks for quiet, there is a higher purpose for your silence. Infinity goes in every direction, even in your body. Search within yourself by allowing different vibrational frequencies to explore.