Another example of science verifying what was already known. You can change how people perceive past events using a number methods including hypnosis & NLP. In this study, they use electrical stimulation but visualization works just as well with people.
"By artificially activating circuits in the brain, scientists have turned negative memories into positive ones.
They gave mice bad memories of a place, then made them good - or vice versa - without ever returning to that place.
Neurons storing the "place" memory were re-activated in a different emotional context, modifying the association"