As fathers go, Ashoke is one of the good ones. We never see him losing his temper with Gogol, or chastising or criticizing him. He is portrayed as so mild-mannered and wise that it's a little hard to see why Gogol avoids his father for so many years.
Maybe Gogol's relationship with Ashoke is troubled precisely because of the fact that Ashoke is so reserved. This reserved manner isn't a personality thing, either. When the family is in India, we see a new side of Ashoke:
Within minutes, before their eyes Ashoke and Ashima slip into bolder, less complicated versions of themselves, their voices louder, their smiles wider, revealing a confidence Gogol and Sonia never see on Pemberton Road. (4.31)
Back in Calcutta, Ashoke feels like he's back in his own skin. He grows confident, and it is clear that he and his wife are at ease among family members who talk each other's ears off. This comes as a shock to Gogol, of course, because he has only seen Ashoke's American persona – the reserved graduate student, who doesn't want to ruffle any feathers.
Though he, like his wife, tries to hold on to Bengali traditions, he also wants very much to make their American life work, and he tries hard to fit in in some ways.
[…] to a casual observer, the Gangulis, apart from the name on their mailbox, apart from the issues of India Abroad and Sangbad Bichitra that are delivered there, appear no different from their neighbors […] There are other ways in which Ashoke and Ashima give in. (3.60)
Ashoke is no fool. He knows his family won't make it in America if they don't make efforts to assimilate. As the family's breadwinner, it's possible that he, more than anyone else, struggles to strike a balance between assimilating into American culture and holding on to his own.
That's something Gogol doesn't quite seem to understand about his own pop. For much of the book, Gogol also does not know about his father's tragic past, you know, the one that led to Gogol's quirky name. It must have been a pivotal moment in young Ashoke's life, because he wound up naming his son after the book that saved his life from the train.
Yet for some reason, Ashoke does not share this story with Gogol until his son has gone to college. That information just may have come in handy when Gogol grew to hate his own name. It's yet another way that Ashoke and Gogol are quite distant from each other.
When Ashoke finally tells Gogol about his past, it adds a new layer to his dad. He is no longer just the stodgy old guy who stubbornly sticks to tradition. The narrator tells us, "Though there are only inches between them, for an instant his father is a stranger, a man who has kept a secret, has survived a tragedy, a man whose past he does not fully know." (5.87)
In the end, though, Ashoke and Gogol have a whole lot in common, despite the fact that they come from different generations. Living a relatively protected life in the United States, Gogol cannot begin to fathom where his father is coming from, and has thought of his father as a symbol of old fashioned cultural tradition.
But once his father shares the story of the train accident, it opens the door to see his old man in a new light. Unfortunately, the great tragedy of the story is that it's a bit too late. While there are moments of connection throughout the novel, Ashoke dies before Gogol has truly learned to appreciate them. Perhaps that's Ashoke's most significant contribution to the novel. He represents a missed opportunity for Gogol to better understand his cultural identity.