Perceptions of duration are an integral feature of social experience. Some dinner parties seem to drag on for hours on end. Others pass so quickly that it is time to leave before we know it. One reason for this difference seems obvious. In some cases, nothing of interest seems to be going on and we feel bored. At other times, we become engrossed in the stories that are told, debates on the state of the economy and discussions of who will win the World Cup. Time seems to pass more quickly when it is filled with many different events than when it is not.