If there is anything about your “self” of which you can be sure, it is that it is anchored in your own body and yours alone. The person you experience as “you” is here and now and nowhere else.
But even this axiomatic foundation of your existence can be called into question under certain circumstances. Your sense of inhabiting your body, it turns out, is just as tenuous an internal construct as any of your other perceptions–and just as vulnerable to illusion and distortion. Even your sense of “owning” your own arm is not fundamentally different–in evolutionary and neurological terms–from owning your car (if you are Californian) or your shotgun (if you are Sarah Palin).