Although you might conceivably live a full life without ever once turning attention back on itself and activating a reflexive consciousness, this ability is nevertheless intrinsic to consciousness. Initially it might appear to be an addition, an extra that is artfully constructed but in the event it is revealed as belonging to a prior stratum of awareness, as merely the activation or isolation of this prior and ongoing action, and in this way it reveals the potential accessibility of even deeper 'events' located in the same general 'direction'. Refinements of letting go seem to be limited only by your ability to actively-passively remain submerged.