What do you think of things along this line: you're are not a confident person. You think you are not attractive, are not smart, and are weak. And you want to change that. So, one of the things you do is positive affirmation. You tell yourself that you are a confident person. That you are handsome and smart and strong. In doing so, you begin to becoming more of the person you tell yourself you are, even if you are not or do not believe it (yet).