We haven't even proven that we actually exist yet. You may think you observe yourself in a mirror and other things around you but how do you prove they actaully exist?
Saying because you see them doesn't wash, as you may think you see them, same for touch, you may think you touch something, but this is only your senses telling you, no outside proof is telling you, and if you think it is, maybe it is only your thinking that makes you think that is proof.
