This is rare. But you do have to allow yourself to relax. The best way around this is to decide that you will relax and know that it is a proven fact that with each subsequent session of hypnosis you will relax more. It also helps if you can change your internal dialogue to one that makes you want to relax, rather than one that confirms that you are not relaxing. Making this suggestion to yourself will get your mind to cooperate. If your mind drifts away, don’t make a big thing of it. Just reign it back in again. At any rate, when you think your mind is wandering away from the hypnosis at hand, that’s your unconscious being stimulated to think of things that are more relevant than you realise.