Recent years have seen an explosion of studies examining behavioural and neural aspects of imagining future events. However, little is known about whether imagined future events reflect future happenings. We examined event occurrence 1 year after participants imagined highly probable future events, specific to place and time. Overall, participants did engage in most of their imagined events. Completion rates were similar to naturalistic prospective memory and implementation intention studies examining personal plan completion. Approximately 20% of events were abandoned. We found participants often imagined events that were repeated many times in the course of a year and this impacted the vividness of recollection, sense of personal importance, personal involvement in event fulfilment, and extent of positive emotionality 1 year later. Together, the results provide an important validation for prospection research and highlight novel dimensions in the temporal structure of future-thinking.