I've spent a good chunk of the past two days - effectively days off - writing GURPS stuff. Not for my game, exactly, but finishing up two co-writing projects with Douglas Cole.
What started as "I'll do a quick pass over the draft" for an project we're writing turned into hours of writing, then a few hours of Doug writing, and then passing it back to me for more writing. Same today.
It's DF related, as is the other one we finally got into "submit for comment" state. We will see what comes of either of them.
Writing is fun, really, and I love seeing something come together and feeling the words just flow out to make rules read in a sensible and understandable form.
At the same time, I'm glad we've gotten to where we are. One of these has elements I need to playtest heavily, and I already have to okay from my most rules-concerned players* to give them a try.
But man it's nice to thing, okay, "what's next to start?" and "let's see how it plays out in actual use" and not "I need to crank out another 1,000 words on this subject and check all the rules references to ensure consistency."
* I'd say rules lawyers, but they're more like rules advocates for the GM. They typically start sentences with things like "I think the rules let me do this, but they shouldn't . . . " They'll abuse things if I tell them that yes, it's supposed to be abused in that way. If not, they'll cheerfully cooperate on fixing it.