https://www.sciencedaily.com/releases/2018/10/181026102619.htm > Researchers at the University of East Anglia (UEA) found the length of time between product or service consumption and posting affects the review given. > For example, the sooner customers post a review the more they 'zoom-in' on their experience, focusing on the more concrete aspects, even on small details, and the more negative they are. As the time increases, reviewers 'zoom-out' and have a more positive view, focussing instead on the general experience and more abstract aspects.