I thought I had sent a system notification yesterday morning but apparently I didn't. So I sent one in the evening, which is the first one there, asking "Is this thing on?"
Then I made another note to everyone about the point I originally wanted to make, that I had sent certain people some private messages about something in particular. It was taking a while for them to reply. Rather than PM them all separately, since I'm apparently a lazybum, as well as the fact that some people don't even notice that they have any PMs, a "Mass Sys-Note" can reach everyone and is harder to ignore.
Most users wouldn't have any PMs from me recently, so don't feel like you're missing out if I didn't send you any. And if you did get one, you might as well reply in some form seeing as how that was the whole point of all this.