When do people make optimistic forecasts about goal-directed behavior? In five studies, we examine how an individual’s recent pattern of behavior affects their predictions regarding the likelihood of sticking to their goal. Specifically, we show that even when the overall rate of behavior is identical, a recent streak of goal-consistent behavior increases the predicted likelihood that the individual will persist, compared to a variety of other patterns. This effect is due to a perceived higher level of commitment following a recent streak. In turn, people are less likely to recommend the use of a restrictive goal pursuit strategy, like a commitment device, after a streak because they believe that it is unnecessary. The effect is attenuated in the presence of other diagnostic cues of commitment (i.e., the individual has a high base rate of goal-consistent behavior) and for predictions regarding behaviors that do not require commitment to a goal. Together, these results demonstrate the significance of streaky behavior for judgment and prediction.