First of all, the leap is:

I don't know. Which is why I want to ramp up and build toward that daily goal. This will allow me to see how long it actually takes me to write that much and then block time out accordingly in my schedule. As of right now, I know I will not be teaching in the fall, so less unpaid work for paid work there. I also will not have a show during November, so another time cruncher will be missing from my schedule. This means, I think, I can block out enough time to write in my schedule.
So far, with just a couple of short sessions, I do see that, as time lengthens, the words per minute decreases. I assume that trend will continue - even though the longer time so far was partly due to a brief interruption.
It seems like an odd thing to just jump into. But not really. I have just come off a very busy time with my other profession and have had very little time to write. Especially not sustained writing periods. I want to try this. NaNoWriMo came up in something I was reading and then in a search for writing resources for a kid referred to me and I thought, why not? It's a goal. It's for fun. It's a commitment I could enjoy and, if I don't make it, nobody dies.
So I signed up. And I could still back out if I change my mind; but I don't think that will happen. I am already loving this challenge to myself and looking forward to connecting with others during the process.
I am also spurred by my workout buddy and I climbing the steps at Mt Tabor. We set that as a goal for ourselves - for later. We thought we'd walk up the hill, look at the steps, maybe go up one flight - and build our stamina up to go up all of them eventually. Instead, we looked at them after climbing the hill and said, ok, let's try two and see. We got to two, paused to look at the view and assess our condition, watched the father and son run down a flight and then start up two steps at a time and pass us. We decided to go one more and that would probably be it. Instead, we made it to the top of that set. We walked up the road a bit and then ran into a crowd gathering for some event ... something about people and dogs. So we retreated and decided to go ahead and climb another three flight set of stairs we'd passed so we wouldn't be run over by the pack of dogs and owners. And we did it! You'd have to know us to know what a feat it was and how we even surprised ourselves. We thought it would be at least a couple months before we'd be able to do all of them.
So when NaNoWriMo kept popping up and I was already thinking how to build writing time into my schedule, I thought of Brenda and me climbing all those steps. I can do it! I thought. And, if I don't make the 50,000 mark - at least I tried. And there's always next year.