I take a close look at Bernard Williams’s paper "Moral Luck," which put this notion on the philosophical agenda. Williams’s focal example is the painter Paul Gauguin. According to Williams, Gauguin’s morally dubious decision to desert his family so as to pursue an artistic career can be redeemed only by his partially fortuitous success as a painter. This is shown by the consideration that a successful Gauguin would not be able to regret his decision, whereas failure would have prompted regret. I suggest that the best way to understand this claim is to see Gauguin’s decision to become an artist as a constitutive decision, which launches what for him proved to be a defining project. One cannot coherently regret the realization of such a project or the decision that gave rise to it because that would amount to wishing to be someone else: conditions of personal identity set the limits on the counterfactuals about ourselves that we can intelligibly entertain. However, not being able to regret the constitutive elements of one’s life is not the same as approving of these elements. So I disagree with Williams’s ultimate conclusion that the inability to regret a decision signals some justification for it, no matter how attenuated.