Accurately judging the confidence that other people have in their own judgements isn't easy. It can be that the other person just doesn't care whether they are wrong.

In political discussions people often argue their positions quite strongly even if they don't have good evidence for them. You might mistake that strong arguing as confidence when it's rather the opposite.

Fight, flight and freeze responses are all instances of fear but look quite different. Especially shy people often confuse a fight response with confidence when it isn't.