Stage hypnosis is more or less an exersize in social conformity, and isn't actually a true form of hypnosis. It is a situation where it is acceptable and expected for people to step outside of themselves. Some are able to do this naturally, others aren't, and the person in one way or another has to be willing to participate. If the indivudal doesn't want to do it strongly enough, they won't.
I know. Everything about him is "LOOK WHAT I CAN DO!"
I'm too lazy to dig up a Stuart gif, but you can use your imagination.