I was an adjunct instructor in a chemical engineering lab for 6 years. Taught a total of about 100 students during that time. I can recall about a half dozen faces but not a single name.
I taught my last class 4 years ago so I can imagine what it would be like to recall someone from about 20 years ago.
Same here. When I worked as a grad instructor, I had anywhere from 80 to 100 students per semester. I can recall many faces, but damned few names. In fact, I may be able to recall two or three names...if I try.