Though I haven't finished Lolita yet, I flipped to the back and read Nabokov's notes on the novel (from a year after it was originally published [published 1955, so 1956]).

First, I was slightly annoyed at how he implied his English work was inferior to his Russian work. Why? Because, to put it simply, the vocabulary used in that novel is nothing short of amazing. Especially for a second (actually, I think it may be third or fourth) language. Of course Nabokov always emphasized the importance of form over content. Regardless, I would sell my soul for the ability to write like that, and him passing it off as minor literature left me in a state of awe.

That aside, this point of his was interesting:

It is childish to study a work of fiction in order to gain information about a country or about a social class or about the author.

Funny, because that's what I've been doing for the last year or so in my American/English/World Lit classes. I think his point is that fiction writing should be entirely fictitious, where it takes place in its own world and doesn't rely on the bounds of reality.

Maybe. And I would agree.

In summary: studying fiction as writing is good, but not if you're looking for a history lesson.