Hypnosis is a process of achieving an altered state of consciousness. It's similar to daydreaming. With your conscious mind occupied or turned off, the messages from the hypnotist go into your subconscious. The effect is that new attitudes and behaviors can be suggested so deeply that they can become as integrated as if you'd been that way for years. For example:
It becomes natural to reach for the water bottle instead of a cigarette. The idea of buying ice cream now turns your stomach. The extra hour or so is just enough time to get to the gym instead of wasting time on the computer.
About 98 percent of the people that want to be hypnotized can be. The volunteers at a stage hypnosis show are picked because they are natural somnambulists -- about 10 to 15 percent of the public goes into deep trance easily. These people tend to be frequent daydreamers, experienced meditators, really creative, really open-minded, really intelligent, young people, dancers, actors, law enforcement, military, sleepwalkers, and previous hypnosis subjects.
A large majority of the clients I see are medium-trance subjects, cataleptics. They initially experience hypnosis as a half-wakeful state. They are often letting their minds wander and then focussing again on the hypnotist. It's a state similar to when you're just falling asleep or waking up (hypnopompic, hypnogogic states). Many learn to go deeper, but even at this level, hypnotic suggestions can be effective. They just require a bit more reinforcement.
