...And found nothing. No drip from the roof. No evidence whatsoever that the inside of the roof had ever been wet, or the ceiling joists, or the sheetrock over the garage ceiling. Dry as a bone, no staining or warping or wetness at all. From the outside of the house, the roof was just fine. On closer inspection, the ceiling in the garage where I thought I'd been painting over wet sheetrock was also A-ok, and showed no signs of ever having been soaking wet. Once I got my face up there where I could really see it, I realized that it'd just been the paint - it must not have been mixed completely.
I feel a bit silly, but that's overshadowed by how incredibly grateful I feel that I don't have a leak in my roof! That could have been a nightmare! Especially since, although my part of town hasn't gotten the pounding that the rest of Austin has been getting this evening, we've gotten some good rain, and lots of it, and there's a bunch more on the way for the next 24 hours or so. WHEW.
P.S. - while we were up there I did, however, find my two nine-foot wooden flagpoles that I'd given up on ever seeing again. As soon as I saw them up there, I remembered that I had taken them up there two years ago to poke a clog out of the dryer duct - apparently I just never brought them back down. Now if I could only remember what I'd wanted to do with them when I realized they were missing... .