I know what you mean, not exactly the same though as I don't perform and have no taste for it, but on some occasions I can turn into a clown and be quite gregarious. A few people who have witnessed me on my good moments, think I should be a stand-up. I've noticed it happens especially if I'm in a small group and I feel confortable among the people I'm surrounded with. But for whatever reason the switch can turn to off or on for a lot of reasons.