The peak-end rule is a psychological phenomenon that suggests our memories of an experience are heavily influenced by the most intense moment and the final moments of that experience. This means that the overall evaluation of an experience is based on the peak of the emotional or physical intensity and the end of the experience, rather than the experience as a whole. This rule has been observed in various situations, from vacations to medical procedures, and can greatly impact our overall perception and satisfaction with an experience. In other words, the peak-end rule highlights the importance of creating positive and memorable moments at the peak and end of an experience to leave a lasting impression.