Overconfidence

Cromwell: rationalise with elsewhere. 'Cromwell's Rule': tendency to be certain about something, rather than to admit the possibility of fallibility. This breaks Bayes' Theorem, because any amount of contrary evidence will be rejected. This is black-and-white thinking (oversimplification): either something will happen (P=1)or it won't (P=0). With imperfect knowledge, we may need to admit shades of grey (0<P<1). Intuition qv can also lead to this oversimplification.

Literally, this is a form of risk-factor-misjudgement qv. Could it be included within that page rather than being a topic on its own?

Because subconscious processes are quick and easy... The selfish and "stupid" people are full of "convictions" while the more clever and/or educated are full of self-doubts. No wonder some are more driven to act than others.[BW] cf black-and-white (probability?). Could bias action to that favoured by simplistic thinkers. cf assumptions qv.

Nobody is infallible. We must all consciously question our preconceptions and strive to objectively evaluate alternative points of view. This is unnatural and requires effort. cf confirmation bias qv. (Is this a thinking trap or is it a solution component?) cf assumptions qv.

Could overconfidence and unconfidence qv be merged; eg, 'over/under-confidence', 'Misjudged confidence', 'confidence misperception'?

unjustified optimism: belief that chosen action will work based on overestimation of our own ability, or because we're entitled or special or destined (eg, Nazi belief that they could establish a third reich). Culture.

cf. risk-factor-estimation qv, adaptation qv.

somewhat opposite of demoralising qv.

Related: assumption qv: we assume that we know more than we do; we're entitled to survive because God says.