You may dislike another person’s certainty because it interrupts your own.

Other people’s certainty is a pressure. When someone is sure, your own position has to either agree or defend itself, and the effort of that can register as dislike of them rather than as discomfort at being unsettled. The irritation is frequently about your own uncertainty being disturbed.

When someone’s confidence annoys you, separate two questions: are they right, and do you like how they hold it. Both can be answered independently. And your own uncertainty is worth defending as a position rather than as a failure to have one.