I think that Bryson has learned a lot on his hike on the Appalachian Trail. One specific thing I think he learned was that it is much more fun and safe to hike on the trail with a friend than alone. At first it seems that Bryson is a little discouraged by being alone but then it comes clear in chapter 17 that he is very determined to hike as far as possible while Katz is gone. This could have been because there had been reports of mountain lion. I think that Bryson became nervous after hearing that there were dangerous animals near the area where he was hiking and wants to get through that area as quickly as possible. Bryson realized that he felt much safer with a partner and in turn that allowed him to enjoy the journey more.