Hypnosis is about controlling the mind. However, we all control our own minds. Even when you are in hypnosis, you have control over what information you will tell a hypnotist and what suggestions you will accept from the hypnotist. The participants in a hypnosis stage show are carefully selected. Anyone who resists the hypnotist's suggestions will be asked to leave the stage, and those that remain on stage are choosing to accept the silly suggestions and perform for the audience. It's like someone pretending to be drunk so that they can get away with behavior they might otherwise be too inhibited to do. However, it is not like being drunk-- you are always in control when you are in hypnosis. If you hear a suggestion you don't accept, you will either ignore it or come out of hypnosis.
Many of us feel like we can't control our minds. We can't control our thoughts. However, controlling our minds and controlling our thoughts are not the same thing. We all have thoughts throughout the day. Thoughts arise just as surely as blood flows. Meditation and spiritual practices can teach us not to attach to those thoughts-- let the thoughts come, notice them, and let them go. If you can resist attachment to your thoughts, then you are controlling your mind. Unfortunately, it can take years to learn how to do this.
Hypnosis replaces negative thoughts with positive thoughts. This is much easier to do than learning not to attach to thoughts. Most of the thoughts we have throughout the day are repetitive and many of those are negative. What we say to ourselves about ourselves is what we tend to believe about ourselves. Therefore, if these thoughts are negative, we feel terrible about ourselves, and if these thoughts are positive, we feel great about ourselves. This is mind control: controlling the kind of thoughts we have rather than allowing the thoughts to control us.