When we are enjoying ourselves we usually tend to overestimate rather than underestimate the period of time that it lasted. Belgian experts say that our memory strengthens if we are actively involved in something, especially if it is a source of excitement.
Therefore, this means that because our memory formation gets stronger we estimate the time elapsed to have been longer than it really was.
To offer a rationale, researchers said, 'Feeling more aroused during a ride was associated with longer estimates of the ride's duration. As it has been shown that arousal leads to memory enhancement, more information is likely to be encoded during a highly arousing event, leading to greater availability of information at the moment of estimation.'