Juster's story is about a boy who is not very interested in anything. Since most young people have, at some time or other, known someone much like the book's hero, Milo, who had too much time on his hands, or as the book describes it, "who didn't known what to do with himself," they should readily identify with the situation.

The Phantom Tollbooth is a book that makes learning fun. Like some young people, Milo does not care much for words or numbers. "I can't see the point in learning to solve useless problems," he says, "or subtracting turnips from turnips, or knowing where Ethiopia is or how to spell February." But meeting people who love learning, and who swear by its importance, makes him wonder.

As he uses words and numbers in his adventure, he begins to realize that learning is vital and necessary. What he is taught in school does make sense. He sees what can happen when people use too many words to say something—or not enough. He can also see what happens when people waste time, or make excuses. These experiences cause Milo to become aware of the importance of education and applying himself, and they can make learning come alive for readers as well.