To know emptiness is not just to understand the concept. It is more like stumbling into a clearing in the forest, where suddenly you can move freely and see clearly. To experience emptiness is to experience the shocking absence of what normally determines the sense of who you are and the kind of reality you inhabit. It may last only a moment before the habits of a lifetime reassert themselves and close in once more. But for that moment, we witness ourselves and the world as open and vulnerable.