I have been told often at my 'Christian' school that I'm insane. Then I started coming back with the response that I was. Very often I find I have the same symptoms as you. What I do to control it is think of a dream. Create you're own dream to drift off to.Much like making up a story.If you mind keeps on coming to a different spot yet repeats what that spot is base a story on that.For example: You're mind, no matter how hard you try, comes back to Lost. Make you're own character and make up a story with Lost.