Yeah, I struggle with this. Often when I see someone my brain doesn't present single name match, more often I have a list of potential matches in my head. e.g. "Scott or Rob" -- so I'm forced to just go with one, or avoid saying any name at all. I've gone for it and botched a name before and it was truly embarrassing. Often given a few seconds I can recall with certainty. It's the one-the-spot instant name recall that is difficult for me.