Lost Launchpad customization

Not sure when it happened over the last week or so, but went to a hot corner to open Launchpad and instead of finding my custom folders at the top of the page, ALL of my apps are displayed over 4 pages with the empty folders at the end.

First, that's really random, I can't think of anything at all I've done that could've caused it. Second, it makes me wonder what else may have happened that I just haven't learned of, yet. Unsettling.

I checked ~/Library/Application Support/Dock and there are no Launchpad databases, only one file, desktoppicture.db. How does a Launchpad database just disappear? Checked Time Machine, and that's the only file in the folder as far back as I can go (even though everything was fine a week ago).