Boldness is a mask for fear, however great.

Loud confidence and terror are closer neighbours than they appear. A great deal of aggressive certainty is a way of getting past an internal state rather than a report on it, which is why the boldest person in the room is often the most frightened and the least able to say so. The performance works on other people and, for a while, on the performer.

Two things to do with that. When someone is overwhelming a discussion with certainty, wonder what they are afraid of rather than matching them. And when you notice yourself pushing hard, check whether you are convinced or just unwilling to look at the alternative.