If you have watched a stage hypnotist, you have seen what looks like one person exercising remarkable control over the thoughts and actions of another. It is fascinating, in part, because we have all seen it happen in real life. Suddenly someone we know seems to be relying on someone else to do the thinking. Even if the influence is good, it is a little frightening.
The secret is that there are no magic words. In order to lead someone into hypnosis, that person has to be willing to go there. Often the people you see on stage are more than willing. For whatever reasons, they are enthusiastic about giving up self control and allowing someone else to take charge. They know that there are limits to what can happen on stage and they are only agreeing to give up control within those limits.
What you see in hypnosis is an agreement between two people. Like all agreements between human beings, it stretches as far as it stretches and no further.
We all let ourselves get talked into things that are not in our best interest. We all do things to ourselves that we would not do to our friends. We all fool ourselves, from time to time. We can be manipulated because we are not always smart or kind - to ourselves. This does not require hypnosis.
To understand hypnosis, we begin by understanding the nature of the agreement between hypnotist and the person hypnotized (not the 'subject' since that implies someone is being acted on instead of acting with). As we understand how to create agreement by setting limits to agreement, we pick up immensely practical understanding about how influence works outside of hypnosis.
We also begin to understand how someone else can be a necessary guide if we are to relax and reach deep inside to find out what we are made of.