Mariah Carey's lyrics to Hero are in reference to to discovering the hero inside each and every one of us. Therefore when she speaks of the "long road when you face the world alone" she is certainly not meaning this in the literal sense, but a more symbolic sense of how taking on the challenges and responsibilities of releasing one's inner hero is a struggle.
The meaning of the poem shows a word "independence" which is opposite to our feelings... she used the symbol "hero" to describe what there is in people's inside(heart).
