Whenever I'm writing something that isn't a novel, with a linear story and accompanying outline, the process becomes more difficult and lengthy. I've been pretty hard on myself for taking as long as I have with my Storytelling Sciences books, but I've come to realize recently that such things are written over time. It's why reference books have editions and are revised often.
In sitting down to finally write the more arcane portion of the SS System I realized that it was something I've been writing for a long time, little by little. I have files written in MS Publisher format that contain text I'm pulling for my current work, that's how far back this thing goes. Think nothing of recounting the play test hours spent and all the people who sat around a table with me at one time or another. Some I don't talk to any more, while others have moved beyond this life.
It feels good to draw near what seems to be the completion of this particular work. Like anything written in this way, it will require revision over time as I find things to add or change. It'll be nice to sit on the other side of that project and be able to focus on the Setting Books and the novels based on them.
Even better, I might get to play the game that I built. We'll see.