I suppose I shouldn't be surprised. (a) I always end up writing a new novel shortly before the current one is done, and (b) I think I have a Law of Conservation of Creativity, by which I mean that once I've made up something I like, I tend to want to spend more time with it.
Regarding point (a), I see this as a psychological prophylactic against attachment to my work. So long as the new new novel is the Shiny Thing, the recently-completed novel can be kicked about and hacked apart and rejected without any personal suffering. Or maybe it's the other way around--maybe I just get tired of a novel by the time I finish it, and my creative mind's impatient to start on the next thing.
The problem with the Not-a-Werewolf book is that I began it during the period of mental depletion that followed the end of the Dickensian Fantasy. I dicked around with that book for a full year before I really got down to business on it. I don't know whether to count this toward its clock, or not.
If I begin the clock with the current draft, it's been just over a year for the Not-a-Werewolf book.
Since the characters and world-building are already relatively stable for the Nascent Book, I hope I can get the clock down a bit further--though I am not going to truly begin it until I finish Not-a-Werewolf (for which I have scheduled a February Deathmarch).
Nascent Book shall now be known as Talking Fish Book, I think.
And also, dear self, it is way, way past time you gave the Not-a-Werewolf book a proper title.