[SirRoderic]

I don't read a lot of full-length books in recent years generally, but as a child I read tons of fiction... I was about to say "...so I don't think I have any trouble," but actually, come to think of it, most of the books I liked as a child were things like Redwall or Warriors, where all the characters were distinct species of animals and things like that.

If the characters are all humans, I think it's difficult to remember who's who because they're just random collections of syllables (names) tied to a set of facts — "Kirk, a human man, is a captain", etc. I think, though, that this may be more of an aphantasia/faceblindness thing (I have no "theater of the mind" and can't picture characters to distinguish them) than an autobiographical memory thing.

On the subject of memory, I will say, though, that perhaps I lack an interest in fiction books nowadays because no fond memories of reading them stick with me; even though I can recount the plot in excruciating detail, the most I might be able to say after the fact is "I liked/disliked that book" in a general sense, and that's just a memorized fact about my immediate feeling at the time. With a nonfiction book on the other hand I acquire information that can be useful to me afterwards.