How does the novel end?

Paddy Clarke Ha Ha Ha, a novel by Roddy Doyle, spans a year in the life of a young Irish boy. The book does not have a traditional plot structure but rather is told through a series of vignettes. 
Paddy (Patrick) is ten years old and the oldest son of the Clarke family living in a fictional part of north Dublin called Barrytown. As the book goes on, Paddy becomes less interested in friends and causing trouble, and more concerned with his younger brother's wellbeing and the fact this his parents fight every night. For a while, Paddy cannot understand why his parents don't like each other anymore and hopes that he can find a way for the fighting to stop, but he realizes things can't go back to the way they were once his father hits his mother. In the end, Paddy's father leaves his family, and Paddy feels that he must be the man of the house.