The purpose of this article is to manifest how a psychological realist text through the techniques of stream of consciousness and internal monologue via an interlocutor narrator can depict what Jean-Paul Sartre calls ‘existential angst' that has become popular in the age of modernism. To accomplish this, the current article uses the psychological analysis research method to analyze the American Jesse Andrews's debut novel and shows how the protagonist suffers from his existential angst, the trauma of the other and the inability to form his identity and, therefore, essence. Andrews's recluse protagonist is shown as responsible for his deeds since he creates free choices to form his essence. Existentialism is regarded as the opposite of nihilism. Therefore, considering himself a nihilist or absurd, as well as suffering from low self-esteem, Andrews's protagonist tries to resist his meaningless life and, then, finally exists. Soren Kierkegaard's concept of anxiety, Sartre's modern existentialism, and Erik Erikson's identity development are briefly examined throughout the study, in addition to other concepts like nihilism, absurdism and trauma of the other. It is necessary, too, to explore the literary genre ‘realism' and the sub-genre ‘psychological realism' as well as the techniques of stream of consciousness and internal monologue, used by the novelist to achieve his goal.