Answer:
1. You earn a sense of self-respect/encouragement. Continuing through the hardships of work in order to achieve what you most want will allow you to take that "deep breath in" of satisfaction.
2. Be able to prove yourself to anyone who says you can't do something or even being able to prove yourself to yourself. Challenging your own expectations again correlates with #1, satisfaction.
3. As you work towards your "dreams," you build up the motivation for other things along the way. Having one rock movement gets you to pick up small other healthy habits along the way along with other motivations.