Who is Chuck Bolger from This Boy's Life and what is their importance?

Chuck is Toby's best friend. They meet at Concrete High School when Toby starts hanging around the older crowd. Chuck is kind hearted, but he hurts himself when he drinks, which is often. Toby likes Chuck better than the other boys in the crowd he hangs with because he sees some humanity in Chuck. Toby lives with Chuck after he leaves Dwight's house.