The irony of insanity
One's perception is all they have to make sense of the world, so what is life even like if you can't trust your own ability to perceive reality? And yet, a significant portion of the population deals with that problem. There are those who adjust to their condition and lead happy, healthy lives, and then there are some sad cases like Maureen where without a commitment to figuring things out, the person feels entitled to hurt others in their insanity. The entire premise is ironic, because Maureen, like everyone, naturally trusts her perception, regardless of what other people say.
Matricide
The act of killing one's mother is ironic because instead of a mother giving life, it's a child taking life away. It's especially ironic here because Mag was allegedly taking care of Maureen. Who knows if Maureen even killed her, because after all, she isn't charged for the murder.
Pato's role
The sexual encounter between Maureen and Pato seems dubious. Why wasn't he aware that Mag would be there? Is he still really there when they're fighting? Because later in the novel, it seems that Maureen sometimes hallucinates Pato, so technically, he could be a figment of her imagination. Perhaps the fight in the kitchen was actually about Maureen imagining things again.
Maureen in Mag's chair
The end of the novel shows Maureen in Mag's chair, a replacement perhaps. It's strange that Maureen would feel comfortable in the chair of her own mother who she murdered. But yet, somehow, this is what feels right for her, perhaps a statement of her own inability to distinguish people's roles.
No charges pressed
Just when the reader begins to feel as if they finally understand the truth of the novel, there is an interesting, silent detail. Why didn't Maureen go to jail for murder? The novel depicts a gruesome death with plenty of evidence, and there's a funeral, so the authorities know about the death, so why didn't anyone say anything about the fact that the death was obviously homicidal? This leaves the reader with the sense that there's still so much we are not being told about Maureen and her strange experience of life.
