Brian's experiences in the woods fundamentally change his relationship to the natural world—that's pretty obvious. But they also transform his understanding of his life before the crash. Both directly and indirectly, Hatchet compares life in the woods to life in the city. Of course, there's better Chinese takeout in the city, but that's not all. Brian's time in the woods makes him appreciate for the first time the ease and comfort of life in civilization, but Paulsen also suggests that that ease comes at a certain price. Sounds like our author is trying to make a statement.
Hatchet suggests that modern man—man in the city—lives an unnaturally easy life, and, as a result, has lost touch with what it really means to be human.
Nature is represented in the book as a scary, dangerous place that the urban man has successfully escaped.