Huh. I couldn't really say what's causing it, but wanted to let you know that you're not alone. I have generally decent luck with remembering faces, though there have been times when I completely did not recognize someone I knew perfectly well. It's disconcerting to be sure. I can't remember strings of numbers either (and my new job is full of numbers -- it's frustrating). It's an all the time thing for me, but I'd say it's worse when I'm under a lot of stress. Are you having a lot of stress? Or even having something you're preoccupied with lately?