They say that it is typical of humans to take risks in almost all situations, poker is no different, the only difference is to risk to win, and to risk an to knowing that you will lose.
Errors and correctness, without them we got nowhere
There is a difference between confidence and stupidity.
You can be very disciplined with your bankroll but still confident. You can feel fear but still feel confident knowing that fear is a natural and good thing to feel to a degree.
Confidence is about feeling fear and doing it anyway, not about being completely absent of fear. You are confusing psychopaths for confident people.