Boy: Tales of Childhood is an autobiography of sorts by Roald Dahl. Since it is autobiographical in nature, the story doesn't have a singular setting. In general, the novel takes place during the 1920s and 1930s. In general, the story is set in either England or Wales. At other times, the story takes place in Norway where Dahl spent summer vacations with his family. While not on vacation, much of the text focuses on the strict educational system Dahl was in and the harsh conditions found there.

I think the answer should focus on the school locations for illustrating how setting helps readers understand character. Dahl was a mischievous child, and he would often be severely punished for his actions, yet readers see late in the book how that strict structure was something that was quite formative for Dahl and that he even thrives in that kind of environment. Readers can see this end result through Dahl's eventual commitment to the Royal Air Force. The strict school environment was also instrumental in allowing Dahl to have such wonderful memories of his family vacations away from school.