What Mr. Perpich meant by “you are the best thing you have is that you will always have yourself. You can use yourself to do all sorts of things. Sometimes you don’t need other tools to do things. You need your hands to eat, or write, and defend yourself from danger and some other things. You need to be able to have physical abilities to do things that other people can’t do, if you have physical abilities. To be positive and have good thinking is to not worry that you can’t do something that you want to do but instead you should believe that you can do anything if you try. If you don’t have positive thinking then you might not be able to do anything, that is what can help Brian if he is stranded in a forest.