The Irony of David's Parents' New Baby
When David finally makes it back home after being away, he sees the new baby through the window first thing. In his hurt, David assumes they have replaced him already. He recalls his mother's penchant for babies. What he doesn't know is that his family has more than enough love to give him and this other child, but David ineligible to understand this abstract concept so young. He's similarly ineligible to decide whether or not to remain part of his biological family.
The Irony of David's Flying
David is told to believe in himself perfectly in order to fly, like the birds. He takes this message to heart and eventually does teach himself to fly. He taps into a special place of feeling whole, but ironically he loses sight of this confident feeling once he is lost in the park. Unable to fly home, his spirits continue to drop, making his return impossible.
The Irony of the Narrator's Past
The narrator befriends David because he is immensely lonely. Having been continually rejected by everyone significant in his life, he believes that he must be defective. If people knew him, they'd leave him. This assumption is ironic because the narrator cannot see past himself in order to recognize the wrong which these people, especially his family, did in leaving him. He looks at himself as broken, but the truth is these relationships should have been trustworthy, in a perfect world. Assuming these people were perfect, the narrator is left concluding that he must be the broken one, the only broken one.
The Irony of the Narrator's Loneliness
Rather than seek out adult company again, the narrator looks to David to be his friend. He is still lonely, however, because he predicts David will leave him also when he grows up. The narrator remains lonely because he forms this premature relationship which is doomed not to last, but he prefers the temporary relief to building strong, adult relationships which have the potential to endure time and age.
The Irony of Growing Up
David and the narrator both are afraid of growing up. Age is the most frightening concept because they have both linked it to loneliness and loss. From another perspective, however, the effects of time on a person make that person more complete, not less. The lessons learned from experiences lived give a person definition and conviction which a child as young as David cannot begin to understand. Ironically his fear of growing up is what leads him to make the very grown-up decision to leave his family.