How we cite our quotes: (Book.Chapter.Paragraph)
Quote #1
Even to myself I had hardly admitted what came sometimes with light and fire; dreams, I had told myself, memories from below memory, figments of the brain only, like the voice which had told me of Gorlan, or the sight of the poison in the apricot. (I.7.3)
These are early days, when little Merlin understood very little about his powers. He's really good at explaining away his second sight or his ability to see through things to understand their true nature. But these insights are not just old memories, or even memories of other people's memories. Merlin actually sees things that others don't. We can't blame him for the confusion.
Quote #2
Looking back now, I see that much of what happened has been changed in my memory, like a smashed mosaic which is mended in later years by a man who has almost forgotten the first picture. Certain things come back to me plain, in all their colors and details; others—perhaps more important—come hazy, as if the picture has been dusted over by what has happened since…" (III.1.2)
It's hard to keep in mind that this whole story is told from the point of view of old Merlin, who is at the end of his life and probably in a pretty dismal situation—but here we have proof of that. It's also a classic sign that our narrator might be unreliable. If Merlin views the past as a puzzle whose original picture he can't recall, it could mean that we're getting a story that never happened. (Although…of course it never happened. It's fiction. Mind blown.)
Quote #3
[…] sometimes now as I search my memory I wonder if here and there I have confused them one with another, Belasius with Galapas, Cadal with Cerdic, the Breton officer whose name I forget now with my grandfather's captain in Maridunum who once tried to make me into the kind of swordsman that he thought even a bastard prince should be. (III.1.3)
This is not the kind of confession you want from your first-person narrator. Merlin tells us, after 225 pages, that perhaps—just maybe—he isn't remembering things right. Even though we've become attached to his characterizations of the people in his life, we have to admit that maybe this isn't the way the story actually played out.
But such is the nature of memory, and Stewart makes us aware that legends are like this: they're put together over huge spaces of time by lots of different people. They're unreliable in a way that we have to accept.