I was a grad student in astronomy in 2005 (graduated last year), and I'd been dreaming about various ways I wanted magic to work in a world for over a decade, so in 2007 I finally started writing. My intent was something epic, a 2- or 3-book-length story that would span years and take years for me to write. I paused after part 1 book 1 back in 2009. Last year, over about 6 months, I wrote a novella prequel to further explore the main secondary character (not a primary, but a secondary who would be most important in the novel/series right behind the two primaries). Then I went to work re-writing what I'd already written based on the new backstory of that secondary character. Now I'm considering branching off yet again, but into a completely different world, more sci-fi along the lines of Stargate (highly advanced race, now extinct, some people use their technology to fight shadow wars, explore, etc.). The idea is not completely different from my magic-themed writings, though, since in that I'm trying to write it as though magic is realistic - it's a 5th force, takes energy, can't violate any rules of physics, magic is controlled via neurotransmitters and glands, etc. ... so it's somewhat mechanistic. In the sci-fi, it'd just be using technology to achieve somewhat similar abilities. Anyway, the point here in my bit o' exposition is back to my subject-line question: When you write, if writing is not your primary job, how side-tracked have you gotten?