Hypnosis is a trance state characterised by extreme suggestibility, relaxation and heightened imagination. It’s not really like sleep, because the subject is alert the whole time. It is most often compared to daydreaming, or the feeling of “losing yourself” in a book or a movie. You are fully conscious, but you tune out most of the stimuli around you. You focus intently on the subject at hand, to the near exclusion of any other thought.