People tend to think that they know others better than others know them. This phenomenon is known as the “illusion of asymmetric insight.” While the illusion has been well documented by a series of recent experiments, less has been done to explain it. In this paper, we argue that extant explanations are inadequate because they either get the explanatory direction wrong or fail to accommodate the experimental results in a sufficiently nuanced way. Instead, we propose a new explanation that does not face these problems. The explanation is based on two other well-documented psychological phenomena: the tendency to accommodate ambiguous evidence in a biased way, and the tendency to overestimate how much better we know ourselves than we know others.