When Brian arrives he thinks that he has no useful materials and wont be able to survive. He then remembers that his teacher Mr. Perpich used to say You are your most valuable asset. And it makes him see that he has enough to survive because he has himself.
Positive thinking is an important theme in Hatchet and it helps Brian get through tough times.
In Hatchet Brian has to be self sufficient and even had to make his own tools and a bow and arrow so he could catch food.
Even after being beaten by a tornado and a moose Brian preservers and starts rebuilding his shelter and weapons.
I'm so HUNGRY.
When Brian finds turtle eggs he restrains from eating them all despite not eating in a while. The eggs provide as a good source of protein until Brian learned how to hunt. Without his patients and restraint he may not have had enough food and would have starved.
IS THAT A BEAR
Survival is a big theme in hatchet because Brian spends the whole book trying to stay alive. Whether it is wild animal attacks, finding food, fire and warmth, shelter, or natural disasters that try to kill him.