I agree with you for the most part, Haruki, although I believe that the guy is the same age but more mature in a way ("our bigger blessing, girl, is being young")--I think he is more self-aware than the girl, who is only eager to grow up, and realizes that their youth is a gift, that being immature is nothing to be ashamed of when you're young, because experience is what furthers the process of learning. His self-awareness, which the girl interprets as him being mature, disarms her and makes her anxious to grow up, but it only managed to make her lose what used to make her special.
I agree with you for the most part, Haruki, although I believe that the guy is the same age but more mature in a way ("our bigger blessing, girl, is being young")--I think he is more self-aware than the girl, who is only eager to grow up, and realizes that their youth is a gift, that being immature is nothing to be ashamed of when you're young, because experience is what furthers the process of learning. His self-awareness, which the girl interprets as him being mature, disarms her and makes her anxious to grow up, but it only managed to make her lose what used to make her special.