After high school, I entered the University of Minnesota majoring in the field of Computer Science. The exercises will be simple in the early chapters and get more complicated in later chapters. This particular exercise is an affirmation. It's not enough just to say the affirmation, you should think about it first, then say it slowly to yourself a few times. Each time you say an affirmation, you should try to put emotion behind your words and actually believe what you are saying.
Affirmations work for many reasons.
First, it's a way to clearly communicate with your subconscious, and we all know how powerful the subconscious is from hypnosis studies. Affirmations also allow you to communicate your intentions to your Oversoul which can help you reach your goals. Third, many people in metaphysics believe that your beliefs directly affect your experience. Affirmations make it easier to change your belief-system, and make positive changes in your life. The most effective affirmations are the kind you make for yourself.