Abstract: This paper considers the question of whether it is possible to be mistaken about the content of our first-order intentional states. For proponents of the rational agency model of self-knowledge, such failures might seem very difficult to explain. On this model, the authority of self-knowledge is not based on inference from evidence, but rather originates in our capacity, as rational agents, to shape our beliefs and other intentional states. To believe that one believes that p, on this view, constitutes one's belief that p and so self-knowledge involves a constitutive relation between first- and second-order beliefs. If this is true, it is hard to see how those second-order beliefs could ever be false.I develop two counter-examples which show that despite the constitutive relation between first- and second-order beliefs in standard cases of self-knowledge, it is possible to be mistaken, and even self-deceived, about the content of one's own beliefs. These counter-examples do not show that the rational agency model is mistaken—rather, they show that the possibility of estrangement from one's own mental life means that, even within the rational agency model, it is possible to have false second-order beliefs about the content of one's first-order beliefs. The authority of self-knowledge does not entail that to believe that one believes that p suffices to make it the case that one believes that p.