Yes I've experienced this too often. A trigger sets it off for me. Sometimes when I'm faced with a fear, like public speaking for example, suddenly my entire body paralyses, I loose all my senses, sight, hearing... I also loose time. I suddenly snap out of this trance state and I have no idea how much time has passed, 30 seconds or 2 hours feels like 1 second for me. But the people around me notice of course and don't understand why I've frozen in time like this. When I snap out of it my brain wipes clear the entire event, like nothing ever happened. But I remember it later and feel so embarrassed knowing that all those people stood there watching me frozen. I've been experiencing this all my life, it was much worst when I was a kid, but I've noticed it still happens even now as an adult.