Dreams should scare the crap out of you. A dream should be so big that it makes you feel uncomfortable to say it out loud. Once you have the dream, start creating attainable goals. Combine several goals, and dreams start to become realities. As this happens, your dreams should get bigger.
The key to all of this, really, really hard work. Never stop chasing your dreams. Work hard and good things will come. Believe in yourself, you’re smarter than you think, stronger than you show, and capable of more than you are asking yourself to do.