This is because Jem has shown in many points of the book his ignorance when it came to mature situations
“How could they do it, how could they?” “I don’t know, but they did it. They’ve done it before... they’ll do it again and when they do it—seems that only children weep"Harper, TKAMB 113).
Simple: I choose this because at that time Jem was the typical rough, energetic, and ambitious American boy
“Goin‘ out for football next year"Harper, TKAMB 120)