In Chapter 22 of Harper Lee's To Kill a Mockingbird, after Atticus responds to Jem's question regarding the verdict of Tom Robinson's trial, "How could they do it, how could they?" by saying,
I don't know, but they did it. They've done it before and they did it tonight and they'll do it again and when they do it--seems that only children weep....
Atticus's mention of children weeping points to Jem's having trouble reconciling his childish idealism with his maturing recognition of reality. When Scout asks about Miss Gates's seemingly hypocritical remarks about Negroes in light of her school speech on the equality of all people, Jem becomes "furious" as he is reminded of the terrible hypocrisy of the jury in Tom's trial. Atticus, of course, recognizes Jem's dilemma and tells Scout that Jem is "trying hard to forget something," but Scout feels that he is storing the incidents of the trial until he can "sort things out."
Throughout the entire Tom Robinson trial, Jem believes that Tom will be found not guilty. Unfortunately, Tom becomes another victim of racial injustice after he is wrongly convicted. This moment is extremely traumatizing in Jem's life because it is when he finally loses his childhood innocence. Unlike Scout, Jem becomes bitter and jaded towards his community of Maycomb. At the end of Chapter 26, Scout consults Jem about her teacher's hypocrisy by bringing up how Miss Gates made a racist comment while she was leaving the courthouse. Jem suddenly becomes furious and tells his sister never to speak about the Tom Robinson trial again. Scout then runs to Atticus, who tells her that Jem was trying hard to forget something but was actually storing it away until enough time passed. Jem is still bitter from the trial and remembering the time when he lost his childhood innocence continues to upset him. He essentially does not want to relive the traumatic moment.