With the last ficathons I participated in some years ago I wasn't inspired by the prompt and then there was so much stuff going on and essentially I didn't start writing until 3 days before the deadline. And then I felt super stressed. For a while when I was wirting Borgias fic, I actually found writing easy. Probably because it was like writing historical fiction (to a point) and I'm very familiar with the time period. I don't know.... different fandoms bring different... well... difficulties.