Well, being hypnotized is not like you see it in the cartoons or in the movies... It's not like you completely lose control of yourself and can't tell what's going on. It's more like a state of very deep relaxation. You're totally "awake" and you perfectly know where you are and what's happening around you.
At least this is what I experienced. I don't know if there are different techniques and if they cause different effects, but I believe you always remain in control of everything while you're hypnotized. This is how my psychologist explained it to me when we tried it.