The mind is inherently outward-bound and cannot be turned inward, so attempting to do so is a futile process that can only be used to eventually frustrate the mind.

“People are talking about turning their mind inward. There is no such thing. You cannot turn the mind inward. You can frustrate the mind by trying to turn inward so that it drops dead out of frustration. But you cannot turn the mind inward because the very nature of the mind is outward.”