Before you can do great things you have to expect them from yourself, and if you do not view yourself as worthy or capable then great things will never be achieved. Self confidence is the fuel that helps to stoke the fires of greatness, and some of the greatest men and women through history expected a lot from themselves. When you expect greatness from yourself then you are always looking at ways to do great things and thinking about how your actions can change society or even the world. In a world where everyone was average greatness would be unheard of, and you are capable of anything that you think you are. What is in your mind is the strongest motivator, and when you expect yourself to do great things then great things will usually follow.
Great hopes and big dreams can be achieved, but only by those who expect to achieve these accomplishments. Your mental stats plays a big role in whether you succeed or fail, and having high expectations of yourself can be a very productive factor. If you want to do wonderful things in your life that help society or advance humanity you must believe that you can, and expect nothing short of this goal. If your first attempts end in failure this is okay, as long as you keep trying and you believe that you can accomplish your goals even when they are great, because eventually you will end up reaching the objectives and be successful in your goals.