Sit someone in a chair, point a camera at them and put money on the table, and their judgement changes in specific, predictable ways. None of it has anything to do with how much they know.
Loss aversion runs the show
People feel a loss roughly twice as strongly as an equivalent gain. On a money ladder that asymmetry is enormous: dropping from a high total feels far worse than climbing to a higher one feels good. That is why contestants walk away from questions they could answer. The fear is doing its arithmetic, not their knowledge.
The audience is not your friend
A room willing you to continue is applying real pressure, even though it costs them nothing if you are wrong. Contestants consistently take risks in front of a crowd they would not take alone. The same effect works in reverse on answers: hearing a murmur when you say an option out loud will make you doubt a correct answer more often than it saves you from a wrong one.
Why you should rarely change your answer
First instincts on factual recall are usually better than second thoughts, because the first answer came from memory and the second usually comes from reasoning about the question rather than the fact. The exception is when you notice you misread the question. That is new information. A vague feeling of doubt is not.
The practical defence is to decide your rules before you sit down – what you will risk, when you will walk, whether you will change answers – because none of those decisions get easier once the lights are on.