how does Brian fell about himself and about his life at the beginning of chapter 16?

Brian has begun to change, and the reader can see this in the way that he no longer keeps track of days, but of events, too. Brian has gone from a suburban kid whose closest contact with nature was a park in the middle of the city to a kid who is able to track and kill a bird. Brian has a bad day. First, he is attacked by a moose, and several of his ribs are broken. This could be potentially fatal under the right circumstances, so it is lucky that he has survived. Then a tornado hits and destroys everything Brian has built. This might cause anyone else to give up, but Brian is simply happy to be alive and determined to continue surviving. This shows the reader how much Brian has changed. He is growing stronger in character.