What we generally regard as self is no more than a chain of momentary thoughts or impressions—a thought construct, if you will. A "self" is not to be found anywhere outside this momentary arising and perishing of conscious thought. Observing the mind's activity like this, one may suddenly experience the insight that mind itself is wholly shifting, unlocalized, and impermanent; or that the subjective "self" is just a thought, an "empty" construct to which we cling needlessly. Rather than the source of all truth and comfort, "self" is the source of petty craving, fear, frustration, and sorrow. By letting go of the thought of self and pacifying its negative influences, one experiences a thoroughgoing release from the pain of samsara. This is known as the unconditioned peace of nirvana and "no-self."