"The Phantom Tollbooth" displays Milo's growth; Leonard S. Marcus in his notes to its annotated edition writes that the boy learns to think in the abstract, pledging after his unintentional jump to Conclusions that he will not make up his mind again without a good reason. Milo does not accept the word of the demon of insincerity that he is a threat and is rewarded by learning he is not. Just for a moment, Milo is able to float in the air beside Alec Bings and see things from the perspective he will have as an adult, allowing the young reader to contemplate what it will be like to do the same. According to Liston, Milo "transforms himself from an unthinking and compliant Lethargarian to a young adult with greater consciousness, a firmer sense of self, and a newly found set of responsibilities".