I'm sure you've seen the #amwriting hashtag here and there. It's meant to show that hey, authors are making progress on whatever writing project we're doing.
I always find myself reluctant to start a big writing project, simply because I know it means that my brain will no longer be my own for months. Seriously. I will have voices in my head, I'll fall asleep and wake up thinking "what would she say to him at this point?" and I will be working feverishly to meet a deadline I've imposed on myself.
I will think, eat, drink, and sleep these characters and this plot for at least 6 months (4 months for some of my smaller books). My life will, in essence, not be my own. It will be shared with them for every waking moment. I will no longer have time for "relaxation" like just watching TV (without thinking how I can use a scene in one of my books), going to movies (ditto), shopping (wondering how my main character would act if she saw shoes like that), and so on.
Does it sound like a grind? It feels like it sometimes. The series I'm working on is somewhat soul-consuming in the sense I've been with these characters for years and I've really put them through hell and back. I've got 2 books to go to finish this series, although I suspect I'll end up doing a bunch of rewrites before I actually get around to publishing it.
For me, #amwriting means I'm in the zone. I'm mostly somewhere else most of the time, not quite here and mostly there, living in my head and at my keyboard, working out plot points and figuring how to get my characters from point A to point B. Don't get me wrong: it's what I do. I love doing it and wouldn't change it for the world. I'm just a little preoccupied for the next 6 months or so. You may need to knock loudly for me to hear you.