As any meditator can tell you, the chattering mind is hard to keep quiet. Try it. Try to focus on nothing. Or, to start a bit easier, try to just sit and watch your thoughts. Watch your thoughts grasp at any straw and weave it into a randomly expanding chain. Soon you can no longer watch the thoughts. You become sucked into their gusts and currents, swept along helplessly, seeing the world only from inside them, losing sight of how they are constructed, of the serpentine trails they leave, and of the things they shut out.
These chattering thoughts are precisely the kind of analytic engagement that most people would call consciousness or self-awareness. And yet the more we become lost in this awareness, the less we are self-aware.