Can you go back and change the past, or are you stuck with what you remember?
That’s the key: what you remember. The fact is, our brains are stuffed with memories, only some of which we retrieve, convincing ourselves we have a true and complete picture of the past when in fact we have a partial, often negative, picture of our history.
Why the emphasis on the negative? Our nervous systems record unpleasant events, including the cues that lead up to them, rapidly. Then they cling as if they were barnacles on a hull. Pleasant things, on the other hand, are stored more slowly and fade more quickly. Why? Because of our need to learn and respond quickly to threatening signals, signals that might threaten our very life.