Become who you want to be, part 2
It is the fact that we build who we are going to be through every choice we make that makes things like positive visulaization or goal setting meditation so powerful (heard of The Secret?).  When you have a clear picture of whom you want to become in the future, i.e. the potential future you that you would like to become, your attention, the small, seemingly unimportant decitions and actions you take every day are much more likely to bring you to that possible outcome.  You will focus on the things you have to do to become that future you.
The problem most of us have is that we want a potential future for ourselves and we do other things that lead us in other directions, towards different potential future me’s and then we wonder why what we wanted did not happen.  In the above example, if what I want for myself in the future is to have a slim body and today I decide to have the muffin, that act takes me one little step towards a future me with a round body, not a slim one.  If I decide to have the salad, I am a step closer to the future me I do want, with a slim body. 
 In my opinion, the basic difference between people who achieve their goals and those that don’t is this.  Having the goal is not enough, you actually have to take the necessary steps to achieve it.  That is what all the “miracle systems” neglect to tell you, they sell more books or talks telling you that if you visualize your goal clearly enough, it will materialize magically for you.  It won’t.  What can happen if you do visualize your future self clearly and strongly enough is that you will reprogram your brain to get to that goal, and you will take the steps necessary to get there without effort.  That is, you will not even think that eating the muffin is an option, you will probably even stop thinking about muffins, desiring them and therefore even seeing them and craving them.  If you are truly convinced of your goal, you will find enjoyment in getting to it, you will actually crave salds, and that is when the magic really begins to happen.