These dramatic rehearsals of how we would act in various situations help us to learn how to adapt and modify our behavior, thus broadening our learning from the original circumstances to various possible situations. For example, a primitive man hunting an animal might realize that if he had thrown his rock a little sooner, he might have hit his prey. Often these reflections are motivated by what we wanted in the situation but were not able to get. The reflective imagination can show us different approaches we might take and what the consequences might have been according to our projected imagination. These reflections can help us to understand our failures and release their frustration by imagining how the situation might have been worse, making us feel glad it turned out the way it did.
Sane people know the difference.
While memory is exclusively related to the past, imagination is generally projected toward the future so that even reflections on the past tend to focus on how we might handle it differently next time. To imagine any change is to create a different future. The past, already having happened, cannot be changed, although our views about it can be changed. Of course all memory and imagination occur in the present and are projections backward or forward. Planning Actions that we perform, except for the autonomic reflexes, are all imagined ahead of time, often subconsciously.