I guess one way of looking at first-person narration is merely as a figurative device; it's not that the main character literally writes all this down as a professionally told story, it's just a symbolic means of getting into the character's head.
A few months ago I read an urban fantasy that shall remain nameless, but it involved vampires.
The narrator/protagonist was a woman in her mid-twenties. The novel was told in first person present tense. Now, first person I'm okay with. I'm okay with present tense; I've written some fiction in present tense, and that gives the text a unique flavor if used properly.
Combine the two? It was like fingers on the goddamn chalkboard.
I won't even mention the sex scenes. Because it's an urban fantasy with vampires, of
course there are sex scenes...
The story was, actually, quite a bit of fun. But the narrative perspective chosen was
really annoying. First person present tense -- BAD!