Why is it that some people (Jellies in this case) can quickly identify a "new" user as an old user, and others, like me can't?

Some people will watch carefully and suddenly call the new Jelly out by their old name. I can’t do that.

I’ve been following a “new” person for about a month, and I just knew that I knew her some how. Today I PM’d her and said, “Who are you?” When she told me it was like, “Duh! Of course!”

Many of you would have known exactly who she was, and very quickly, but I only knew it in a general, vague sort of way.

Why is that? I’m also bad with face recognition, too. My husband is excellent at it. However, he isn’t so good with names. If we see someone we know, he can tell me where and how we know them, and the name will come to me.