Do you remember being really young and imagining what it would be like to travel somewhere far away and how much fun that would be? Or how amazing it would be to visit an amusement park? Or dreaming about someday driving a car wherever you wanted to go? I used to do this a lot and spent loads of time drifting off into my imagination, which was a fun place to be back then.
This is because when children use their imagination, they tend towards picturing a good future instead of a bad one, while also visualising the positive emotions that might be felt within their fantasy. Then along comes adulthood and gradually imagination starts being employed in the exact opposite way.