Obi left Nigeria for college in England at the typical age. Isolated and alone in a foreign country, he fell in love with his native land. He longed for it in that nostalgic, homesick way that caused him to paint an idealistic picture in his head, which bore little resemblance to reality. When he returns to Nigeria, he's not quite prepared for the reality he faces. He is forced to confront corruption that exists in every segment of society, while combating certain social customs that are socially restrictive, like restrictions on marriage. These cultural values are still entrenched in Nigerian society despite the introduction of Western values and Christianity. As a result, Obi finds himself increasingly isolated and alienated from his friends and family and, ultimately, his lover.
Although Obi's western education alienated him from his friends and family and gave him a new set of values, it could not prevent him from falling back into the corrupt system at home.
Although Obi displays classic symptoms of what has been called the "postcolonial identity," it would be insufficient to blame his downfall simply on his alienation from his mother culture and tongue.