I think the chimney sweep part refers to the time in the 19th century when orphan boys or boys that were sold by their parents who were sent up chimneys to clean them. They often died before their teens as they had developed lung cancer and diseases of that sort. I think this song is supposed to be from the point of view of a boy in this position who is answering a question along the lines of, "If you could be anything in the world, what would you be?"
I think the chimney sweep part refers to the time in the 19th century when orphan boys or boys that were sold by their parents who were sent up chimneys to clean them. They often died before their teens as they had developed lung cancer and diseases of that sort. I think this song is supposed to be from the point of view of a boy in this position who is answering a question along the lines of, "If you could be anything in the world, what would you be?"