The ability to look at your own performance in a analytical and considered way, and to recognise and accept your own mistakes, is certainly useful to a pilot. It's also useful in most walks of life.
However I don't think that there is much in private pilot training that makes private pilots more likely to be minded as such.
I also think that many people who feel that they are minded that way, might not be as analytical and clinical about their own behaviours as they believe themselves to be. But of course they can't see that
