When I ask Zia Haider Rahman just how similar he is to Zafar, the protagonist of his debut novel, In the Light of What We Know, he mockingly hesitates and answers, “67.5%.” It’s obvious he’s heard this question several times before, perhaps even gotten tired of it, but the similarities are undeniable: Both Rahman and Zafar were born in Sylhet in rural Bangladesh to peasant fathers, moved to London as boys after the 1971 Bangladesh war, grew up relatively poor and went on to study mathematics at Oxford on scholarships. Cambridge, Munich and Yale came next for Rahman; Zafar went to Harvard, but both landed in Wall Street investment banks before careening into careers in international human rights law, a move that briefly took them both back to Bangladesh. Charming, articulate and self-professed introverts, they even share a talent for working with wood and renovating houses.

“The truth is that there's a good deal of autobiography in many novels,” Rahman says. “Philip Roth did not write a novel about a Trinidadian South Asian settling in the English country side, V.S. Naipaul didn’t write a novel about modern Turks in Istanbul and Orhan Pamuk didn’t write a novel about Jews in New Jersey in the 1950s,” he continues.

Rahman talks exactly the way he writes, meandering again and again into the thousand tangential thoughts that fill his mind, ruminating on them at length. It’s why his 500-page book can’t really be neatly described in a few words. Yes, there is a basic story, but it’s buried deep under delightfully insightful “digressions” on topics as diverse as the 2008 financial collapse, the bloody history of Bangladesh, Englishness, class, cognitive science, Central Asian politics, mathematical theory, Bach, literature and Western do-gooders in Kabul. Each such digression is an essay in its own right, eager to inform, analyze or simply to impress. Pages are thick with footnotes, characters are full of facts and anecdotes, and every chapter begins with at least two or three epigraphs. “I have friends who say, ‘Whenever I talk to Zia I feel like I should be taking notes,’ ” he jokes, launching into a full-throated, gasping laughter.

Rahman’s favorite character in the book, incidentally, is not Zafar, despite how much they have in common. That distinction goes to the American-Pakistani nameless narrator, who first meets Zafar at Oxford and on whose London doorstep the book begins, with the arrival of the disheveled protagonist. “What I love most about the narrator is that he doesn’t quite get it, that he’s blind to certain things,” Rahman says. He points out one such instance: The narrator, who spent some time in Princeton as a child, remembers Sergey simply as a Russian-Israeli graduate student in chemistry who was around their house “all the time.” Sergey would hover about the mother while her husband was away, helping her prepare meals and making her  laugh. One day he disappeared without warning, failing to return the narrator’s bicycle. “The women all understand these two [Sergey and the mother] must have had an affair,” Rahman reveals. “But the narrator’s memory is fixated on the bike and he doesn't see any metaphorical significance in his father wanting to get a lock for the bike.” I don’t have the heart to tell Rahman that I didn’t catch that scandalous subtext either. In Rahman’s book, much is left unsaid, relying on the reader’s ability to read between the lines. Again and again, stages are set, hints are dropped, circumstances are built, the reader is walked right to the edge and then left alone to make the leap, or not.

As we near the end of our conversation, Rahman confesses that he isn’t all too happy about being done with the book, because it represents the end of something that he found rewarding. “Remember that scene in Star Wars, right near the beginning, when Luke Skywalker and Obi-Wan Kenobi commandeer the Millennium Falcon to Alderaan, the home planet of princess Leia?” he asks. “They arrive at Alderaan, except Alderaan isn't there. I think I felt a bit like that.” It’s a little odd to hear a Star Wars reference from an author whose book quotes Sebald, Naipaul, T.S. Elliot and James Baldwin. “I thought at the end of it,” he continues, “there would be a sense of something accomplished. Instead there was emptiness because I was saying goodbye to these characters, and that was sad.”

Nidhi Chaudhry is a freelance writer currently based in Singapore. Follow her on Twitter.