Long ago, no I'm not going to Google you can if you care to, I read about a study that monitored brain waves when people made mistakes. It was based on simply writing a paragraph, repeating a bunch of words, etc. There is a specific signal in the brain, a particular wave, when people realize they made a mistake and have to backtrack. Alcohol, and benzodiazepines as well, suppress this signal.

That means the conscious mind has to deal with mistakes that the subconscious already knew about but was unable to tell it. At that point rationalization kicks in and it's no longer a mistake, God damn it I meant to do that.