Where we come from we frequently get reminded not to dream too big, not to try and be anything special. If you try to make your dream come true, but somehow fail or struggle, it ironically can bring comfort to the people around you that never made their dreams come true.
But if you were lucky enough to end up with somewhat of a decent self image and confidence, you just might find that anything is possible. The song tells you to keep going if you trust the path you're on. In this dog-eat-dog world you gotta stay Tuff!