Zee words

It interests me that when I am writing for one of my, if you were, peripheral fandoms, I can easily write 1000+ words in a sitting, I don't find I need to be in the mood, I don't find I need do more than, perhaps, peruse a chapter of two of canon or perhaps check a reference or quote (Wimseyfic in particular, I'll often check exact phrasings in canon).

Yet, although most days I write at least some Riptide, I will sit down to write and procrastinate; I will take two hours of writing time and write nothing until the last ten minutes; I will stare at the last sentence I wrote; I will agonise over plot.

(I rarely check Riptide canon while writing, I generally watch eps separately to writing. Perhaps I may know this canon rather well...)

It wasn't always thus, or perhaps I should say it isn't always thus, as I occasionally have bursts of exceptional output, like that one time I wrote a 12k fic in a single day (in about 18 hours, to be fair, and I was, I believe, laid up with a broken leg at the time. It was Sole Survivor for anyone interested) primarily, I think, because there was just no place I could stop and leave the boys in limbo...

I don't think it's a crafting thing, I mean, I don't think it's that I'm putting more effort in, exactly, as I always try to get voices/settings etc right, and I'm possibly pickier about Wimsey, Heyer, etc as the worlds are that much more different than this one. And in theory I should not need to strive to get my boys' voices right (or at least what I think is right) as I appear to have had a wee bit of practice.

Admittedly, I rarely have an outline, so "where to from here" is a thing, and sometimes I must wait for those ratbags to get out of bed and tell me what happened next (a curse, I assure you). But then I don't outline in my other fandoms either, and I rarely have much more idea when I begin, of where I'll end.

Who else finds differences between how they write in different fandoms?