Why do I lose all my confidence around one particular person?

You lead well with almost everyone, and then one person walks in and your confidence collapses. Suddenly you are deferring like you are not in charge at all. That is a strange, humbling thing to notice about yourself. But the fact that it is one specific person tells you something important: this is not about your competence. It is about an old pattern that person happens to trigger. Somewhere in you, this person is standing in for an older authority — a parent, a boss, someone whose approval once felt like survival. Your body reacts to them, not to the actual peer or board member in front of you. That is why the collapse feels automatic and out of proportion. You are not responding to this person. You are responding to a ghost they resemble. So the next time you are with them, name it quietly to yourself: this is the old feeling, not the real situation. Then do one small thing you would do with anyone else — hold a view, finish a sentence, disagree once. You do not have to feel confident to act it. Acting it, in small doses, is how the ghost slowly loses its grip.