<p>Philosophers of mind and philosophers of science have markedly different views on the relationship between explanation and understanding. Reflecting on these differences highlights two ways in which explaining consciousness might be uniquely difficult. First, scientific theories may fail to provide a psychologically satisfying sense of understanding—consciousness might still seem mysterious even after we develop a scientific theory of it. Second, our limited epistemic access to consciousness may make it difficult to adjudicate between competing theories. Of course, both challenges may apply. While the first has received extensive philosophical attention, in this paper I aim to draw greater attention to the second. In consciousness science, the two standard methods for advancing understanding—theory testing and refining measurement procedures through epistemic iteration—face serious challenges.</p>