What you say about yourself will begin to determine who you are, who you become. Your habits are how you embody a particular identity and I think that makes them particularly powerful. But we can also look at the opposite. There's a word for beliefs that don't have evidence. We call it delusion. So my argument is to let the behavior lead the way to make it till you make it. And eventually you have every reason in the world to believe that aspect of your story.