It is impossible to know our own mind in the same way it is impossible for a camera to photograph itself. Of course, the camera can always be pointed at a mirror, and in essence that's what we do to establish our own sense of self.
But what is seen in the mirror is remote and inverted — an external rather than internal view. The camera cannot turn upon itself and photograph itself from its own point of view, and we cannot think about what we are thinking about, except to render our thoughts as remote and temporally displaced.
