Theme
One theme is never judge someone on how they look. Josh saw the hermit and thought he was this really old mean guy who stole everything in the forest that bothered him. The old man actually turned out to be pretty nice to josh when he went back.
The second theme is think before you do. Josh knows there is a chance other people could be walking or riding on that trail and he carelessly rides his bike around the corner very fast then hits a person. He hits the man and then his bike is stolen so now he has to walk the 2 miles back home because he was stupid.