Increasing evidence suggests that multiple cognitive and motivational processes underlie individual differences in happiness (Lyubomirsky, 2001, 2008). One behavior that is associated with (un)happiness is self-reflection or dwelling. We hypothesized that unhappy individuals would be inclined to dwell about themselves, and that this behavior would have a variety of adverse consequences. Three studies tested the prediction that, unlike their happier peers, unhappy participants would be sensitive to unfavorable achievement feedback, likely to dwell about its implications and, hence, show impaired attention during important academic tasks. The results of Studies 1 and 2 showed that unhappy participants who had "failed" relative to peers subsequently displayed increased interfering thoughts; spent the most time performing a portion of the graduate record examination; and later demonstrated impaired reading comprehension. Study 3 experimentally induced versus inhibiting dwelling and found that the manipulation only impacted unhappy students. Implications of our results for the consequences of dwelling for work and social functioning, as well as for detracting from enduring happiness, are discussed.