I know why I'm not doing it.
Oh, I have the time, and, assuming that this little energy-low blip disappears as fast as it came, I can write prolifically enough that the word-limit wouldn't even begin to be a problem. The thing is, see, I know it wouldn't be any good. I'm the kind of writer who pretty much can't sit down, think of two names for important characters, dump them down somewhere and then write what happens to them. In algorithmic terms, I'm breadth-first, not depth-first; I need to have the whole shape of the thing ready before I so much as set pen to paper, pretty much. It's how I write books and papers, and it seems that I'm stuck with that approach for any kind of writing. 80% of the time thinking; 15% of the time actually writing; 5% polishing. I don't do multiple drafts, I don't have to juggle chapters, all because everything's already worked out.
Problem is, with something like a novel, that process takes a deal of time. Far longer than the month I'd be allocated to produce the thing in. And forcing it just doesn't work. I know: I've tried. I've just looked over some of the stuff that's sitting in my In Progress directory. The Vortex I haven't even started writing yet, because some of the ideas are there, but many aren't, so I know I'm not ready with it yet, and that's been incubating since April; right at the back, there's A Different Drummer, of which there's about 6000 words of synopsis, and I don't know what shape it ought to take. It keeps turning into an opera, and I really don't need that level of complexity. That's been sitting there since the back end of 1999. It's going to be a big project, whatever it is, and I'm almost nervous of going anywhere near it. Then there's lots of other stuff that hasn't got to the point of pluckable ripeness yet. Short fiction is so much easier, since even though what's in it may be very intense, it's not so spacious. That I can do pretty much as the ideas hit me: vide the York Trip stuff I did for reparo - that just came in a flash and was written almost as quickly. There's actually stuff left out of it, because writing stuff as LJ postings, I always get the feeling that anything too long just won't get read.
*chuckle* I was digging through some packratted stuff the other day and I came across some writing I did maybe about 15 years ago when I was in my M John Harrison phase, and, you know, I still think it's rather good if you like that kind of thing. First couple of paras? *grin* Good. Knew you would.
It is said by some (who should know better) that the mazy lanes of Semirinal represent the gross structure of the Heaven; that, by inspection of the rusty leaves that are blown along them, one may determine the fates of men and of cities; that the very catcalls of the squawking urchins that infest the cobbled courts and plazas prefigure the lamentations for the great.
It is not so.
And then there's the little one-page myth I wrote for my roleplaying group... Gods, I did enjoy my writing then.
Yes, I could sit down and write The Vortex in a month, but it wouldn't end up being what I know I want it to be. It'd be wrong. I wouldn't like it.
Good luck, NaNoWriMoites, may your Muse play nice with you. I shan't be joining in: not this time, at least.