Hypnosis has been used by physicians and faith healing by preachers to cure people. At first, you are likely to believe that an experienced hypnotist could perform impressive feats but you couldn't possibly do much. That is a reflection of the stories you have read and movies you have seen. They have more vivid, richer imagery. It is not necessary to be hypnotized in order to have vivid imaginary experiences.
Daydreams are vivid.
This is also called goal rehearsal. The idea is father to the act. Perhaps the most astonishing is the control of pain. One of the easiest experiences to have is relaxation which can counteract fears and stress. If your behavior or someone else's is hard to understand, the key is likely to be uncovering the thoughts and images occurring between perceiving the situation and responding.