DNFed halfway through, for the following reasons:
The writing style is very grating. It tries to mimic Victorian writing but it comes across as a forced caricature. Way too flowery, not natural, melodramatic, frankly annoying sometimes. Not to mention jarring when you remember that the protagonist is writing his story at the very end of his life, in the 1980s.
Zebulon is meant to be unlikable, but he isn't unlikable in a fun way. I love the underdogs, the selfish and the self-serving. Zebulon Finch is either boring and unaffected, or melodramatic when he tries to exhibit any deeper qualities. At a young age, he develops a taste for the unseemly and plays pretend at being a thug despite having known nothing but privilege his entire life. He leaves said life to live amongst immigrants in Chicago where he gets involved in organized crime, which he actively enjoys. His decision to leave his home was perfectly reasonable, since his mother was psychologically abusive. Everything else is kind of ridiculous. Do I think this is meant to show that he is born perhaps without remorse, since he enjoys causing innocent people harm for money? Probably. Is it completely laughably played out? Absolutely. Besides, characters who are violent or capable of abusing others simply innately are boring. Sure, it does exist, but it has no payoff in fiction because I want to see some actual motives and watch a character become who they are. I digress.
To show that he has a less callous side, at 17 he develops a crush on a sex worker. He then recalls his teenage "romance" with her over the next 9 or so years of his life. She is just as melodramatic and dreams of having a family with him, because... sentimentality, I suppose. And because it's juicy (and not at all tired and shallow) to write a character who has no agency over being a prostitute, without actually talking about the systemic issues that led to it. Then she gets fridged (disappears without a trace, later we find out she died of preventable illness) so that Zebulon can angst about it and act out. Another female character sacrificed for man-pain, which he constantly recalls like she had a deep impact on him, yet as a reader she had no impact on me and I could barely remember her name 50 pages later. I assume I am supposed to feel this way, to find Zebulon's lingering attachment silly knowing he ruined it for himself (though her motives were unsatisfying, I have to say), but the result is the same. As a character, she existed and died for him to be upset, even if I am meant to find him selfish for making it about himself.
The parts of his personality which he infuses his narration style with are highly obnoxious. He's very keen on comparing things to women's bodies, often in puzzling ways. Vines looks like a girl's hair after sex, Jell-O jiggles like decolletage, bathtub plumbing resemble, and I quote, "a well-endowed female" (which, though probably intended as a 'joke', calling women females... instant gag). He hesitates to sidestep a woman because of their "hips and chests and countless other parts you dare not nudge". I can't say I've ever encountered a women I could not walk past because of her grotesquely large breasts and hips, nor do I know what those "countless other parts" could be referring to (seriously, someone list even one, I'm confused). It's all a bit... honestly, cringe. I wanted to find a more evocative word for this, but it's frankly just cringe. It is speculated that Zebulon's brain will forever remain in the physical state it was when he died, so he will forever be mentally 17. But by simply experiencing things and being in new situations, his brain should form new connections, even if his, say, decision making skills remain like those of a 17 year-old. So, how many lived years on earth do you think it takes to stop finding boobies funny?
The plot went nowhere, and many characters acted in ways that were completely unnecessary or unjustified. The reasoning behind some of their actions felt questionable. One character wanted to have another better suited character replace him for a task, and how does he find an excuse for needing a replacement? Shooting himself in the foot. The character was not written as unhinged enough for that to work, it seemed like there were many other things he could've done instead, so it became unbelievable.
The plot also seemed to just happen to Zebulon. At least four (4) plot points or resolutions, some major, happened because someone contacted him, walked through the door, found him, or specifically sought him out. He sort of stays where he is and people come to him and make things happen. This can definitely happen in someone's life... maybe once, twice if you live long. But it's the only way the plot moves forward is through this device, which is frustrating. Only halfway, around page 300, does Zebulon actually make a decision and act upon it.
The rest of the plot, from what I could gather, also chronicles his life through increasingly unbelievable events. None of which I think will be interesting to read about, especially not when they feature a character that does not grow as a person. I cannot put up with this kid not learning a single thing for even one other miserable anecdote.