This is fascinating. So you know that you've met someone before. You know things about them. But you don't recognize them? What does this mean? You don't remember their name? You don't know why or how you know them?
Ironically, I'm insanely good at remembering faces. But it's kinda useless because of the name thing (and equally, the face context is also difficult).
The interaction described goes like this:
"Hi there, I'm ABC, nice to meet you, what's your name"
"...Huh? I'm XYZ. We've met before."
"Oh right...sorry, I promise I remember you! We knew each other from there, and we've worked on this and that together, and etc. etc. etc. I'm just terrible with faces, I'm so sorry!"
It's not "you know things about them without recognizing them"; it's "you don't recognize them at first, it gets awkward, and so you recite facts about them prove that you didn't forget who they were"
I think normal people are more likely to have the experience where they can't remember a name and why/how/where they know someone from. I of course forget things like anyone, but that's unrelated.