It is often taken to be intuitively obvious that if one is in a given conscious state, then one knows that one is in that state. This alleged obvious truth lies at the heart of two very different philosophical doctrines fithe Cartesian doctrine that one has incorrigible knowledge about one?s own conscious states, and the view that one can explain all conscious states in terms of higher-order awareness of mental states. The present paper begins with a description of the real-life (...) case of Simon Browne, a man who believed he had no conscious states whatsoever, although all external evidence overwhelmingly suggests that he had. This case as well as other cases of what can be called?being in denial? figives reason to reject both the alleged intuitively obvious truth and the two philosophical doctrines which attempt to exploit it. Having abandoned these doctrines, it remains to give an account of Browne?s condition, which picks out both why it is possible and why it is so unusual. This is done by arguing that Browne?s belief is contrary to evidence which he absolutely ought to accept, and that this is necessarily, not just contingently, unusual. In addition, it is shown how Browne?s philosophical beliefs about the mind?body relation contributed to his odd belief. (shrink)