Over the course of the novel, Oskar struggles with existential terror because his recently deceased dad was the person who made him feel safe and secure. To cope with this loss, Oskar makes up rules, such as avoiding heights, and inventions, like a birdseed shirt, to create scenarios that guarantee his safety in a dangerous world. He also turns to science, the way his dad organized the universe, as when he plays the interview with Tomoyasu in his class and describes how atomic bombs work instead of focusing on human loss. His quest for the key, therefore, much like his last Reconnaissance Expedition with his dad, is also a quest for meaning, to make sense of both his dad’s death and his place in the world. When his quest offers up no real answer, he returns to his dad’s grave in order to face the truth that he may never know how his dad died. Although Oskar still mourns his dad’s death at the novel’s end, instead of repeatedly imagining the moment of his dad’s death, he focuses on their last moments together. Even though this rewinds time, it shows Oskar realizing that he still has those moments of love and safety in his life.

Extremely precocious and strange, Oskar is a difficult character to interpret because he doesn’t act like a real nine-year-old and, therefore, seems less like a real character and more like a metaphor. Some scholars have suggested that Oskar offers an impressionistic look at the loss of innocence and sense of safety that Americans and, in particular, New Yorkers felt after 9/11.  Oskar’s fervent invention and establishment of rules to protect himself from a dangerous world mirrors the United States’ rush to create elaborate and often ill-conceived rules and regulations that did more to soothe Americans psychologically than create any true security. Another interesting parallel is Oskar’s complete disinterest in history and past wars, as evidenced by his confusion at Mr. Black’s journalistic career. Before 9/11, many Americans did not know about al-Qaeda or the complex history of America’s involvement in the Middle East. Despite his being a possible stand-in for all Americans, Oskar is still an individual, evidenced by his pacifism, the way he misses his dad, and veganism—traits irrelevant to any sort of metaphorical reading.