Sam may be an independent young man, mature beyond his years, but he still needs some help if he's to live off the land. Enter Bill. Bill shows up one night and teaches Sam how to build a fire, an essential skill if Sam's going to get by on more than just nuts and berries. Bill lives in a cabin in the woods, so we can be fairly confident that he knows what it takes to live out in the wilderness.
Thanks to Bill's help, Sam's able to cook himself a nice fresh meal of catfish; he's never enjoyed a meal like that in his whole life. At the same time, Bill respects Sam's independence. He'll show him how to build a fire, but what he won't do is hold his hand. If Bill did everything for Sam, it would defeat the whole purpose of living independently off the land.