When I worked at Yardi, I knew everyone. You could give me a name and I could tell you their title, their department, and what office they were in. I could tell you if they were related to anyone else in the company, I could tell you any previous names they went by, or their nick name, or their actual name if they went by a different name. There were probably 800 people in the company when I left. If they were in my office (about 250-300 people) I knew them by sight as well.
Since the semester started I have run into two people from previous classes (summer semester and both fall and spring of last year), both of them knew my name immediately, I have no idea what their names are. For one of them it wasn't until after we had ceased talking that I even remembered what class I had with them.
So that skill is gone apparently.