If you have examples of studies that verify that people are always aware of the gaps in their memories of why they did things rather than their memories sometimes "filling in the blanks", so to speak, I'd be interested. My impression is that the opposite has a lot more evidence in studies (e.g. around the reliability of eyewitness testimony).

It's not clear to me whether you're aware of a rigorous basis for your claim or you're just inferring based on what you think makes sense, but I can't help but wonder if it's the later, in which case regardless of the mechanism, the outcome certainly seems to resemble what happens with LLMs.