It is enough to know what you are not. You need not know what you are. For, as long as knowledge means description in terms of what is already known, perceptual, or conceptual, there can be no such thing as self-knowledge, for what you are cannot be described, except as total negation. All you can say is: ‘I am not this, I am not that’. You cannot meaningfully say ‘this is what I am’. It just makes no sense. What you can point out as ‘this’ or ‘that’ cannot be yourself. Surely, you cannot be ‘something’ else. You are nothing perceivable, or imaginable. Yet, without you there can be neither perception nor imagination. You observe the heart feeling, the mind thinking, the body acting; the very act of perceiving shows that you are not what you perceive. Can there be perception, experience, without you? An experience must ‘belong’. Somebody must come and declare it as his own. Without an experiencer the experience is not real. It is the experiencer that imparts reality to experience. An experience which you cannot have, of what value is it to you?
— Sri Nisargadatta Maharaj – I Am That – p. 2