I've been writing full time for the past three months. That's 8 to 12 hours per day, usually 6 days per week. I force myself to NOT write on Sundays, which is a chore...
While I was working as a Benefits Administrator NaNoWriMo was my break--during the busiest, nastiest time of the year, it gave me something else to focus on, some reason to come home rather than burying myself in work to the exclusion of all else and driving myself into the asylum by the end of December (an annual trip, pretty much).
Now, working full time at writing, it's a very different proposition.
I could go into all the stuff that was different, but I now realize that NaNoWriMo was my escape. I don't need that "escape" on the same level now, so the motivation is different.
My goals during NaNo were not so much different from my regular writing schedule--2000 words per day, 6 days per week gets me to 50,000 words by November 29th. I relaxed some of my writing rules a bit for the month and focused on this story specifically rather than writing one and editing another, but for the most part my focus didn't change.
I'll probably do NaNo again next year, but I think I'll focus on things other than word count. By next November hopefully I'll have targeted my goals and be able to work on those goals while I play.