Why does Patrick agree to take Maisie and Grant for the summer only when Clara implies the job is beyond him?

The narrative begins shortly after Sara’s death. In what ways is her presence felt even though she doesn’t physically appear in the story?

Patrick and JED discuss the moment they knew—in retrospect—that their childhood was over. Clara refers to Patrick as “the world’s oldest child” (39). Does Patrick’s childhood ever end? How does his childishness prepare him for dealing with two kids in mourning?