Would you believe that it took me 1-2 years to figure that out? I swiped that little arrow awkwardly with my mouse for 1-2 years, before I accidentally hit a key to get that login screen. I think the issue was that I'm sitting in front of a graphical user interface, which to me means using a mouse. It never occurred to me that I had to hit a key on a keyboard to get a login screen on a graphical user interface.

I think that's when I cursed at GNOME, blew it away, and installed MATE.