What additional lessons does Granger teach Montag?

 Granger teaches Montag that there are ways of rebelling. He teaches Montag about patient perseverance. Granger and his group memorize books; this way the books may burn but the knowledge is not lost. Although Faber saw this dystopia coming, he failed to actually subvert it. Granger and his friends decided to do something that the state could never comprehend. They taught Montag that a state like this would eventually implode on its own lack of meaning. Then they, the intellectual hobos, would be ready to rebuild a new society with substance.