First NaNo I've managed to do that (I think I missed 2 or 3 times before?), although my monthly word counts lately have been reasonably strong so I was approaching NaNo with a good deal of momentum. I was a bit worried I'd burn out, since my energy was flagging last month where I had a few really bad days.
Anyway, I'm still on track to finish the first draft of the full novel by the end of the month (which will give me the complete NaNo experience), and then I'll probably start to look over it right away while working on a new one.
All in all, the drafting has been going pretty well. I had the initial idea for the book several years ago, although I've gone in a different direction in places.
I hit the 50k mark today, and though not officially registered anywhere I think I can still declare myself a NaNoWriMo winner.
I've actually loved the experience and am really excited about the story I've started. I guess I'm about halfway through the first draft, so I will plough on and finish it. At this writing pace it will needs loads of reworking, re-writing, editing etc. As well as a massive amount of research. But that's been the case with anything and everything I've written. I've always adhered to the "writing is rewriting" philosophy.
Anyway, the number one thing I've learned is something I knew anyway, so it was reinforcement rather than learning: don't wait for inspiration in order to write, sit down and start, and soon you will find that inspiration.
I was so excited when I reached 50K this morning I forgot to post here. This was my first NaNo, and I only participated because I'd finished the fourth draft of a different WIP in October with enough time to throw together an outline for a new story I'd been noodling over for a while.
Anyways, this was the most steadily productive writing-wise I've been for years. I really enjoyed it and I can't wait to get enough distance from this story to be able to see the best ways to make it stronger.