I told myself I'd hit 20,000 words on the first day just like I did last year. It was a struggle. The first five thousand or so were the hardest not in the writing itself but making sure I set up the portals between the world in a way that wouldn't create major screwups ten thousand words later. It was still a consistent flow of writing, but nowhere near what I can normally write. This worried me in the later hours as the hours ticked by and I was doing as much goofing around on Twitter as I was actually writing. Whoops. During dinner and 14,000 words I did the math and determined that it was still possible to write 20k in a day; I just had to get myself in gear and actually write.
This also went more slowly than expected, even after introducing another alternate version of my main character, so I turned to Write or Die for a couple of sessions and a nearly guaranteed way to push myself to write a thousand words in fifteen minutes, thus knocking a significant chunk of remaining word count out of the way.
The later evening hours brought tiredness, slower writing, and more typos. The last few hundred words of the last Write or Die session, lasting from 11:40 to 11:55, was ridiculous in the number of typos I produced. But I was a determined one. Those typos could be fixed as long as the word count is preserved, so I pushed forward and hit 20,043 words at 11:55 pm. Victory.
The rest of the month will be much more reasonable in terms of daily word count goals, so day one will always show up as my most successful day on my NaNo user stats page (which by the way is awesome). The three-day novel taught me that writing 20,000 words two days in a row causes my back to revolt. We don't want that, do we?