Back in high school especially, I used to think I had trouble recognizing people. Around that same time I noticed I had quite an easy time remembering other information such as phone numbers. I did try playing blindfold chess once or twice; managed to complete about eight moves before giving up in disgust.

Although I don't think of myself as having a hard time remembering people's faces, I do occasionally find myself failing to recognize someone, even someone I thought I knew fairly well, when I see them outside their "normal" environment. Other times, though, I'll see someone on the street a block away and they'll look familiar, though I may not be able to figure out who they are till they get closer.

For whatever difference it makes, when I try to remember what someone looks like, if I get any mental image of them at all it's usually abstract, like a Picasso, not detailed like a DaVinci.