I know what you mean, there was one point where the narrator just announced the word trystero, and introduced it as being the word to control her for the rest of the book, but I also never understood her true motivation to pursue the matter to its conclusion. Especially when every time she found a new lead or something, she would go out of her way to avoid it. Maybe that goes along with the idea that she was never meant to find the whole truth out, or was always to on the verge of discovering it like the epilepsy simile.

Her whole characterization did change for no apparent reason. All of sudden the people around her are changing, dying or just leaving. Perhaps that was the books summery means when it says she discovers herself or whatever. As for whether or not the whole was real, idk. The whole time I was kind of thinking schizophrenia in the back of my mind, like the people she talked to, and all the muted horns poping up everywhere was unlikely. After all, in the beginning she saw that uncle sam hallucination. But on the other hand I queestion if the author would have known enough about the disease to properly write about it, since Idk the status of schizophrenia research in 1965.