“Christine Falls” (post 2) by John Banville, writing as Benjamin Black: Protagonist has memory gaps, even when he is not intoxicated

“…all mingled to suggest to Quirke something he could not recall, something from the far past that hovered on the tip of his memory, tantalizingly beyond reach. All of Quirke’s earliest, orphaned past was like this, an absence fraught with consequence, a resonant blank” (1, p. 58).

“…and again something spoke to him out of his lost past” (1, p. 63).

Comment: Memory gaps—which happen even without intoxication, in a person, like Quirke, who has no medical or neurological cause for memory problems, for things that he would have been expected to remember—suggest multiple personality. 

However, since there is no indication that either the plot or character development has intended to imply multiple personality, why does the author portray his protagonist this way?

Of course, Quirke’s experience as an orphan may eventually help him to explain how Christine Falls died, and the solution of the mystery must be delayed to hold the reader in suspense. But that did not require Quirke to have memory gaps. He could have had complete memory for his past all along, but only be delayed in connecting what he remembered to the current case. So his memory gaps, per se, would not have been necessary, and there would have to be some other reason for the author to portray his protagonist this way. 

1. Benjamin Black. Christine Falls. New York, Picador/Henry Holt, 2006.