People often forget and sometimes fantasize. This paper reports a large-scale experiment on memory errors and their relation to preferential traits including time preference, attitudes toward risk and ambiguity, and psychological characteristics such as anticipatory feelings. We observe systematic incidences of false memory in favor of positive events and positive amnesia in forgetting past negative events. Both positive delusion and positive confabulation significantly relate to present bias, but this is not the case for positive amnesia. In an intraperson, multiple-self model, we demonstrate that positive false memory, rather than selective amnesia, serves to enhance confidence in one’s future self in equilibrium, thereby accounting for our experimental findings.