It is not something that I consciously set out to do, a sort of penitential walk down the memories of my life. Usually there is very little penitence involved. Nor does it seem to be some kind of perspective seeking exercise, a means to examine the errors of my life and learn from them.
No penitence. No learning. Just that shock of the bad decision and the moment right after it, played over and over again.
It surprises me how vivid these memories can be. I have difficulty remembering important items for my employment or a conversation I should have knowledge of, yet can remember a situation that happened 5 years ago - or 30 - with an accuracy that would put any film maker to shame. Not just the decision, but the time, the scene, the cast of the sunlight, the scents that were present and of course the decision that inevitably went horribly wrong.
I would love to say that there is some usefulness in all this - and to a certain extent, I suppose that there is. I find I write far more clearly about my failures and regrets than I ever do about my successes, partially stemming from (no doubt) that ability to remember them so clearly (I suspect Augustine of Hippo suffered from the same thing; his Confessions have a lot of rather sordid details in them for someone that eventually compose The City of God). But the ability to write well of them seems a scant reward for the suffering that one endures in recalling them.
Just let go, you suggest? Easily said in words, more difficult to perform in practice. In a way, regrets are often like music from your youth: you cannot hear it dispassionately but will always find yourself caught up in where you were and what you were doing when you heard that song (Example: Don't Stop Believin' by Journey, first heard in a specific gym on a band trip in 1981). There are too many emotions caught up in the experience to ever just become a dispassionate viewing exercise.
Just do not remember? Ah, there may be the rub. Perhaps I can choose not to remember, but should I? My regrets often contain within them the seeds of the decisions that did work for the best; the stupidity or greed or lust that were revealed at the denouement for the dead ends that they truly are, leading me to both do better the next time and to ultimately make decisions not based on things like these.
But perhaps there is a third reason: somewhere buried within the inability to unlive an emotional moment or the learning experience that came out of it, there remains a certain part of me that takes a sort of perverse joy in reliving such things, the constant replaying of a song or clip from a movie until it has burned itself into your brain until you cannot forget it. I wonder if this would have less to do with an inability to forget and more with that inner core which, knowing we could have done differently and better, extracts the only revenge it knows: the pain of endlessly reliving the times it was ignored.