Watch the Video first:
Poor Karl. Lets try to help him clear up his confusion. Fortunately, we have philosophy at our disposal to provide some answers in our time of need (where else could you possibly go?). To get at some kind of an answer lets start with Descartes who thought he had a solution to this problem. The short answer, as you should know by now, is that you are a mind, not a body.
Descartes proposed 3 main arguments for what is called substance dualism which is the position that the mind and the body (i.e., brain) are two completely different types of things (i.e, substances). Because my main goal is simply to present the general position, for our purposes we'll only look at two of the arguments.
Recall from the 1st meditation where Descartes shows that we can doubt everything, including the existence of our own physical body, except that we think and that we exist. Because we can conceive of ourselves as existing without having a body, we must not be identical to our body. Since we are not identical to our body, our minds and our bodies must be 2 completely different sorts of things (he calls them "substances").
(P1) All extended things are divisible. (It's possible to divide the body or matter into parts)