"The reader should realize himself that it could not have happened otherwise, and that to give him any other name was quite out of the question." – Nikolai Gogol, "The Overcoat"
We'll tell you what's up with the epigraph. It's awesome, that's what. Not only does it shed light on the themes of the book, it references the title, the name of our protagonist, and a particular moment in the book, too. That's one hard-working epigraph.
The epigraph refers to a passage in Nikolai Gogol's "The Overcoat," in which the author explains that the main character's mother named him Akaky Akakyevich because she just didn't like the other names under consideration. In other words, the sentence quoted is pretty sarcastic. In Russian, the name Akaky unfortunately sounds way too close to the Russian word for feces, kaka, and the name seems to doom the main character to a career as a very humble clerk, a figure of fun and mockery.
Right off the bat, then, we might guess that this book is about a protagonist who experiences a similarly unfortunate relationship to his first name. Sure enough, a few pages in we meet Gogol. Then, when our hero is in high school, he reads this story, "The Overcoat." We can't help but think that when he got to this line, a bell must have gone off in his head.
In addition to giving the reader a wink and a nod towards the main character of the book, the actual content of the epigraph highlights some of the themes as well. It's as if this character, Akaky, could not have been himself if he had been named something different. Similarly, our Gogol becomes quite a different person when he gives himself his new name (Nikhil, which, by the way, sounds an awful lot like Nikolai). But in the end he realizes that his name is Gogol for a reason: it could not have happened any other way.