Narcissism is characterized by a preoccupation with fantasies of unlimited success, power, beauty, and similar values, which has been discussed as intra-individual regulation of a grandiose, but vulnerable self-concept. To explore where the narcissistic mind wanders, we used an experience-sampling approach in a sample with large variability in pathological narcissism inventory scores. Multilevel modeling revealed (1) more mind-wandering in participants with higher levels of narcissism and (2) a difference in the content of these thoughts (more self- and other-related, past and future oriented, negative content). Critically, (3) in high levels of narcissism, the self-related thoughts were associated with more positive valence and were also more future oriented. The results demonstrate the validity of the assumed grandiose, self-absorbed view of oneself in narcissism, which includes self-indulgent fantasies of future success. We also found additional evidence for negative, past-oriented thoughts in narcissism, a dysfunctional pattern reminiscent of rumination, possibly linked to increased psychopathological vulnerability in narcissism.