In searching for hidden objects, infants younger than 12 months frequently commit "A-not-B errors," in which they successfully search for an object in one location (A) and then fail to search for it when it is conspicuously hidden in a new location (B). The question is why they fail to make the switch and perseverate at the first location. While these errors have often been attributed to cognitive limitations, we argue that they are consistent with early learning. We present an error-driven account of "A-not-B," suggesting that learning to make the switch involves attending to appropriate contextual searching cues. We also elaborate the findings of an eye-tracking experiment with 9 month-olds that behaviorally confirms the predictions of our learning model.