Nabokov seems to have borrowed the idea of using a crazy narrator from Edgar Allan Poe, who used such a narrator in "The Tell-Tale Heart." Humbert must be crazy if he takes such reckless chances with an underage girl. He is violating the Mann Act outrageously. Instead of transporting a female across a state line for immoral purposes, Humbert is transporting Lolita all over the United States. His prose style is deliberately intended to give the impression that he is able to function but not completely sane. He uses puns, jokes, plays on words, digressions, all kinds of allusions, free associations, quotations, phrases in foreign languages, and other devices to create the effect of being mentally abnormal. He had to be psychologically unbalanced to act the way he does in the novel. His murder of Quilty is described in a surrealistic fashion. He does not care about being arrested or even executed for his crime. Humbert makes many disparaging remarks about Sigmund Freud, suggesting that he does not believe he is psychotic. One of Nabokov's favorite books was James Joyce's novel Ulysses, which is also full of fragments, puns, flashbacks, and other stylistic eccentricities. Edgar Allan Poe and James Joyce both served as models for Nabokov to draw upon in writing Lolita.