Thought process: you fuck up. You do X when you should have done Y. Why didn’t you do Y? You say “I don’t know”, and it’s possible you don’t, but the short answer is always that some part of you preferred X, or that it feared Y. Either it’s not a standard that is authentically yours–you are pretending to yourself and others–or some part of you fears growth and the following capabilities and responsibilities that will go with it.
In both cases, you can mask these facts by beating yourself up. This is true even before you add the social dynamic. Let’s say you cheat on your wife, and she does not find out. You choose to beat yourself up for a while to deal with the guilt. After a while, you get tired of it, and cheat again. One of two things are happening: either you don’t believe in marriage, or you are married to the wrong woman. In my world it is OK both to remain a bachelor, and it OK to divorce a woman you don’t love. What is not OK is lying, and guilt is what allows you to forestall hard choices. Many people can avoid hard decisions across lifetimes, but it eats at some part of the noblest part of their souls. Sometimes you just have to jump in the deep end.