I am now over 30,000 words and I realized last thursday that I made a tactical error after I finished writing for the day.
A word of advice for other NaNoWriMoers, don't make the mistake I made. Don't read through what you've written so far. It's terrible stuff, it's the first draft and it created an overwhelming urge in me to revise.
So I had to stop writing for a couple of days in order to get back to the mindset necessary for pumping out 50,000 words in a month. I've decided I'm going to put my work away for a month in December and let the dust settle. Then I'll come back to it.
I have a new mantra when I start writing tomorrow.
It's "Revise in January! Revise in January!"