When we experience some traumatic change in our life – whether it’s the passing of a parent, a painful divorce, or, God forbid, the death of a child – as much as we might yearn to go back to the way things once were, it is impossible. What was behind us no longer exists as we knew it, not because it changed but rather because we changed. It’s kind of like how the house you grew up in did not get smaller; you got bigger. What happened in the past changed who you are, and now you cannot return to that old you because that you no longer exists.
This is a painful truth to accept, especially when we are in a dark hallway, scared and unsure of what lies ahead. When we are stricken with doubts and fears about the future, our brains reflexively tell us that the past was better; and whether this is true or not, our tendency is to believe it. So it is understandable that instead of running forward to the unknown our instinct is to run backward, toward what is known: the past.
— Sherre Hirsch, Thresholds, p. 160-161