That space between your ears—that’s yours. You don’t just have to control what gets in, you also have to control what goes on in there. You have to protect it from yourself, from your own thoughts. Not with sheer force, but rather with a kind of gentle, persistent sweeping. Be the librarian who says, ‘Shhh!’ to the rowdy kids, or tells the jerk on his phone to please take it outside. Because the mind is an important and sacred place. Keep it clean and clear.