When I was a kid, the house where we grew up had a staircase. It went up half way, had a landing, turned and then went up the rest of the way. One night, I was going up the stairs and looked up to see an old woman in a long dress with her hair up in a bun standing there on the landing looking at me. I was frozen with fear, couldn't move, couldn't say anything. She turned and went up the rest of the stairs, and I wouldn't go up there, even though my room and the bathroom were on the second floor. I must have stood at the bottom of the stairs not moving, barely breathing for fifteen minutes.
I never saw her again and didn't say anything about it for the longest time, but was having a conversation a few years ago with Little Brother #1 and learned he had seen her too, multiple times. We have no clue who she was or why she was there, but he validated what I'd seen and vice versa.
So, to answer your question, I stood there like an idiot without being able to move or speak, and then didn't talk about it for over twenty years. :)