Weird Mac problems

Today has been full of odd things happening on my Mac. The mouse movement is too fast and unpredictable. Arc is suddenly saving everything to the Desktop instead of the Downloads folder, which is clearly configured in Settings. Ghost keeps changing its behavior on the home page. (I know this isn't a Mac-specific thing, just something else that's weird today). I'll try a quick CleanMyMac->Reboot dance and see if that helps.