While I haven’t any way of knowing for sure, I’m guessing that most of us have things we’d prefer to forget. My speculation is based on what little I know of humanity. Among the standard human truths is this: notwithstanding our indisputable individuality we’re basically doing the same thing. And that includes making mistakes.
It is relatively easy to accept the logic of letting it go, where the “it” is something or someone unpleasant to us. It makes no sense to cling to a sinking ship, to remind ourselves remorselessly of the sadness we’ve endured because of some relationship or some event. The task is however significantly less logical and considerably more emotional when the topic extends beyond mere fact and circumstance and encompasses the thorny matter of conscience. Conscience is the wild card in an otherwise strictly empirical situation. Once conscience has insinuated itself into the assessment of the topic it is virtually impossible to ignore it. Conscience introduces scruples.
The slippery aspect of scruples isn’t the characterization of right or wrong but whether we submit to our inner voice or let it go. Nobody likes to be wrong. Sometimes there are ways of avoiding the condemnation. Rationalization sometimes affords leeway in these matters. Conscience is however so insidious that even if one were successful in disproving a wrong, the very real risk persists that you will never sleep until you have listened to your conscience and removed the weight from your mind.
Giving vent to our sense of right and wrong comes with consequences just as avoiding it does. My experience from childhood (when I first lied to my mother but later confessed) is that ignorance of one’s conscience is a perpetual plague and the result of repentance is far preferable to the possible advantage of undetected deceit. This flies in the face of the facetious adage that honesty is the best policy as long as you’re not in trouble. Juxtaposed to the counsel of perfection is the pragmatic angle that there just happen to be certain events in life which are best left uncovered where at all possible. This may entail some active participation in a cover-up, a risky business at best but one which on a balance of considerations may be preferred.
With time even a conscience can be placated, not so much because it is ever really appeased but more because it just gets buried and smothered like the details that we covered in the first place. Once again however there is the possibility that the tomb will be discovered. This is a regrettable torment to have looking over one’s shoulder.
The good thing about the popularity of being wrong is that there is also the equally common virtue of humanity to forgive. In the legal context there are specific judicial pronouncements which allow for an admission of guilt without the penalty of sentence, the so-called “Absolute Discharge”. To gain such a privilege however the accused must normally plead “guilty”. It is the very act of contrition which affords the compensatory escape hatch. The decision about whether or not to plead guilty is obviously a highly charged tactical choice in a forum where one party has an obligation to prove the case against the accused beyond a reasonable doubt. Where however the context is less formal the choice reverts to strictly personal inclinations. It comes down to compunction and qualms whether to let it go.