"God, time flies when you're having fun, doesn't it?"

How many times in our lives have we either said this expression or heard it? A lot if you're having fun, because people genuinely believe time seems to pass faster when you are enjoying yourself.

But the latest findings from psychologists are calling this belief into question, the Daily Mail reports.

Their study reveals that when we recall an exciting or happy time, we tend to overestimate rather than underestimate the period of time it lasted.

The Belgian experts believe that feeling actively involved in something strengthens memory formation, so we should think that the time elapsed was longer than it really was.

The study included questioning people after a "typically posiitve" fairground ride.

The lead author of the study, Sofie Frederickx of the University of Leuven, said people had to estimate how long the ride was in minutes and seconds. The results showed that the people who felt positive after the ride were the people who estimated the time of the ride to be longer.

"Feeling more aroused during a ride was associated with longer estimates of the ride's duration," the researchers wrote.

"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."

The findings are published in the online version of the journal Applied Cognitive Psychology.