How to know when to read the forward

I want to say, first off, that had I not read the library's copy of Lolita first I would not have read the forward to Pale Fire. I am a a creature of habit and like constancy, so when I saw that Lolita, or what one would think was the first page, did not start at 1 but at 6 I realized that the forward was in actuality part of the story, as normally forwards, prefaces, and the like are counted with tiny Roman numerals. It is harder to tell on our copies (if you have one from the bookstore) because the copy editor numbered each page after the cover, highly irregular, so the story (counting forward) starts at page 13, go figure.