Do We Really Know That the Body Is a Physical Thing?

Do we really know that the brain is a physical thing? After all, if the character that you seem to become in your dream has a couple of glasses of wine, his perceptions will change. So could it be that our bodies, what we call bodies, are not really physical objects? They are how the localization of consciousness appears just as the character that we seem to becoming in a dream. We cannot perceive mind with our senses. Through sense perception we cannot see a thought.