Spoiler Alert: The Controlling Irony
The novel revolves around an Eternal Sunshine of the Spotless Mind–type procedure that can remove unwanted memories. The book starts with the protagonist considering undergoing this procedure. About midway through, however, he learns that he has undergone the procedure once already, but part of the process is not remembering doing so.
Unwinding
One of the ironic aspects of the procedure is that it is subject to failure. This failure commences a process called unwinding. The ironic part of unwinding is that the patient begins to remember everything that they paid the company to ensure they forget. While this is ironic, most people would probably refer to simply as malpractice.
You Can't Forget Some Things
The protagonist originally seeks out the memory erasing procedure because he wants—to put it as simplistically as possible—to forget he is gay. That he unwittingly considers undergoing the procedure a second time for pretty much the same reason is certainly ironic on one level, though the full extent of the irony is problematic. It is both ironic and predictable and that is not a typical combination.
Spoiler Alert: Cruel Irony
That the protagonist has already undergone the procedure but doesn't remember is an absolute necessity to the mechanics of plot. On the other hand, there is a plot twist which is an example of cruel irony of the type few ever see coming. The driving motive of the protagonist, remember, is to have painful long-term memories surgically removed. A brutal assault is the engine which initiates the unwinding process, but the physical damage to his brain also leaves him with the inability to store newly formed memories.
Anterograde Amnesia
The condition which causes the inability to store newly formed memories is the same as that experienced by the protagonist in the film Memento. Because he will literally forget anything that happens within a very short period of time of it taking place, he keeps a record of his recent past via Polaroids, extensive notes, and even tattooed reminders. The full extent of the irony of the following bit of narration by the protagonist of the novel will not be revealed until the end of the chapter at which point the full tragic scope of his condition suddenly dawns on the reader:
"What's anterograde amnesia?" I ask. It sounds familiar. I think she mentioned it before my procedure, but I can't remember what it is.
