Research on retrieval fluency suggests that, under different recall constraints, recalling past failures might be as effective as past successes for engineering task performance. In the current study, students recalling three instances of academic success correctly answered more items on a knowledge task than those recalling nine instances. Other students, asked to recall nine instances of failure, answered more items correctly than those recalling three failures and more than those recalling nine successes. This pattern was partially mediated by the assessments of one's ability as compared with other students. The results are interpreted as extending previous research in retrieval fluency by suggesting that the ease of retrieving task-related instances informs individuals about their comparative ability that, in turn, influences performance.