That never bothered me unless it was in a work situation where it’s more about networking.
However, in a personal setting, I am usually reluctant to introduce myself. I think most people are a bit unnerved by how I avoid answering their questions. I am also happy to be forgotten, as it means I have nothing that I need to follow up on. If I do chance to have an interesting conversation with someone, then I am usually mortified when they remember me (because I’m horrible at recognising faces).
It is amusing how people try to place other people though. On the other hand, is it not embarrassing to the other party that (rather than you being a nobody) they have made a firm demonstration of their inability to pay attention to people?