In chapter 13, we see Brian exulting in his ability to transcend his challenges in the wild. He is thrilled that he has mastered the art of spearing and catching fish for food. With his newfound triumph, Brian becomes more hopeful about his future.
As his victory has been hard-earned, he allows himself the luxury of letting his guard down. However, he soon realizes that this is a miscalculation. In the wild, finding food is the chief aim of every creature. Without food, there can be no life.
In chapter 14, he learns this lesson the hard way. One night, he sees a skunk dig up his buried turtle eggs. Brian watches from his shelter and is almost amused at the scene. He throws some sand at the skunk, hoping to dissuade the creature from digging up the rest of the eggs.
Because he doesn't make a more concerted effort to repel the skunk, the animal makes no move to retreat. Instead, it lifts up its tail, aims, and sprays Brian from four feet away. The noxious, sulfurous liquid hits Brian in the forehead and eyes. As a result, he becomes completely blind, and the effect lasts for two hours.
When he can finally see, he notices that his eyes hurt. The pain lingers for two weeks, leaving Brian disheartened and angry. Fortunately, he learns from the terrible experience and begins to understand the critical importance of protecting his food and building a strong shelter.