Writers, happy for no reason

I'm having one of those rare Squee! days where the sun is shining, the ocean is sparkling, a cool breeze is caressing my skin, the birds are singing and even the plants seem happy.  Stupid grin.  Singing.  The whole Disney deal.  And instead of leaving it alone and just enjoying the moment (or the day if it lasts that long) I have to know what made it happen, because it's been a very ordinary morning – just editing draft, liking a particular scene I'd written and thinking there wasn't much...