“Why I Live at the P.O.” is a monologue in which the narrator, whom the other characters call “Sister,” explains how she came to leave the family home in China Grove, Mississippi. In the process, she reveals her own character and a good many family secrets.
According to Sister, her life with her grandfather, her Uncle Rondo, and her mother had been harmonious until the Fourth of July holiday, when her younger sister, Stella-Rondo, left her husband and came home, bringing with her a two-year-old child named Shirley-T, who was supposedly adopted. Sister immediately made it clear that she did not believe that story. Stella-Rondo avenged herself that night by persuading their grandfather, “Papa-Daddy,” that Sister wanted him to cut off his beard. When Uncle Rondo got drunk and wrapped himself in Stella-Rondo’s kimono, Sister insists that she came to his defense. She also sees herself as the heroine of a confrontation with her mother. After Sister insisted that Stella-Rondo had given birth to Shirley-T and then mentioned a disgraced female relative, Mama slapped her. Sister lost her last ally when Stella-Rondo persuaded Uncle Rondo that Sister had made fun of him for wearing the kimono.
Defeated, Sister collected everything that she could possibly claim and moved to the post office. She comforts herself with the the knowledge that as long as her family members refuse to enter the post office, they will not get their mail.
“Why I Live at the P.O.” is funny because all the characters in the story, including the narrator, use warped logic to justify their irrational behavior. Sister’s down-to-earth language in describing her family is another source of humor, and the fact that Sister has her own agenda makes her comments even more amusing. It is hardly surprising that “Why I Live at the P.O.” has been called a comic masterpiece.