As I noted in an earlier post, I am an "official" NaNoWriMo winner, having written over 50,000 words of about half a novel, which is a prequel to my Invaders trilogy. This novel, tentatively called The Tale of Mat Fartraveled, needs a lot of work, so I'm kind of setting it aside for the time being, as it will have to be rather extensively revised, and I will probably change a number of things within. But I haven't decided exactly how, at this point, although I know I"m going to make the beginning a lot shorter, so I can get a lot more into the action. There's way too much "backstory" where there shouldn't be, among other things.
But all of this is another story. As for the things I've learned, it's like this:
At first, I wasn't even sure that I could write 50,000 words in a month, but I did. And I found that I only had to work at this about 2 hours a day, to turn out a decent sized chapter, which I didn't know previously. This is going to change how I work on my other material. Seriously. I should also note that since most writers have other jobs they must perform in order to support themselves and their writing, or they have "family" obligations of one sort and another, it is important to know that you can put aside a relatively short part of your day to devote to your writing, and get a lot done!
Second, I learned writing discipline! I sat down and wrote something, even if it wasn't very sensible, each and every day. Again, this is something for any writer to keep in mind.
Third, I started out basically, with just a single character, who is prominent in the trilogy, but deserved "his own" story. To begin with, I had only the vaguest idea of what this was, though I know how it's going to end -- basically in a way that leads into the trilogy, but can stand on its own reasonably well.
Finally, although I discovered that many people who participate in NaNoWriMo may be competitive overachievers who write great chunks or whole first drafts, those of us who are not competitive overachievers can still accomplish great things. It's not "competition", but persistence that counts! And if you expect to get yourself published and read some day, you must be persistent in pursuing your goal, and you must believe in it as well.
NaNoWriMo is over for this year, but not forgotten, and never will be. I am going to participate again next year, though what I plan on doing probably will be "all" science fiction/adventure, not "historical". In the meanwhile, I hope to get my trilogy in much better shape, though the first draft is in a lot better shape than it was when I first wrote it. For now, I just feel happy that I've accomplished what I set out to do!