It is absolutely fine and totally normal for your mind to wander during a hypnosis track. You do not need to listen to the track again if this happens. As long as you are listening undisturbed with your eyes closed, the track is working. Ignore what your conscious mind is doing - it’s not relevant when it comes to hypnosis. You can be thinking about your shopping list or how annoying the itch on your leg is or how loud the birds are etc… it’s all fine.