A Logical Philosophical Reason Why You Can Let Go of Your Regrets and Past Mistakes (Without Cognitive Dissonance)

Print shows Maud Muller, John Greenleaf Whittier's heroine in the poem of the same name, leaning on her hay rake, gazing into the distance. Behind her, an ox cart, and in the distance, the village.
fig. Regret (Gast, 1868)

Why Does Regret Feel Bad?

The burden of regret and the powerlessness to go back and do something different is a heavy load to bear. Our free will means choices, and the inevitability of choices, in turn, means that some of our decisions will be evaluated to good and some to bad in the future.

The (seemingly) bad decisions lead to regret (Roese, 2005). That is okay, but why does regret cut deep in the heart? Because regret implies personal action (or inaction) (Connolly & Zeelenberg, 2002).

You Are Not Your Past

The person who made that decision to act (or not act) that way was another you, who is no more. That you was guided by his principles, indoctrinations, understanding of the world and self, and mental and physical state. That you from the past has no bearing on current you.

For a lucid and entertaining explanation of this concept of "personal identity", kindly watch a ten-minute talk at https://youtu.be/17WiQ_tNld4?t=7m19s (also embedded below):



Similar views are expressed in a Ted Talk at The psychology of your future self  (also embedded below) where the author, Gilbert (2014), claims, "The person you are right now is as transient, as fleeting and as temporary as all the people you've ever been. The one constant in our life is change."



So What?

Since the person who chose to act (or not act) in the given scenario was someone else with beliefs and situations different from you, you (i.e. your current self) is not responsible for those actions. Thus, you have to stop regretting the actions of someone else.

Don't be hard on him and (current) you, he had his own reasons for acting that way.

References

Connolly, T. & Zeelenberg, M. (2002). Regret in Decision Making. Current Directions In Psychological Science, 11(6), 212-216. http://dx.doi.org/10.1111/1467-8721.00203
 
Gast, J. (1868). File:Maud-Muller-Brown.jpeg - Wikimedia Commons. Commons.wikimedia.org. Retrieved 14 January 2017, from https://commons.wikimedia.org/wiki/File:Maud-Muller-Brown.jpeg

Gilbert, D. (2014). Transcript of "The psychology of your future self". Ted.com. Retrieved 14 January 2017, from https://www.ted.com/talks/dan_gilbert_you_are_always_changing/transcript?language=en#t-209684

Roese, N. (2005). What We Regret Most... and Why. Personality And Social Psychology Bulletin, 31(9), 1273-1285. http://dx.doi.org/10.1177/0146167205274693