I don't think I have face blindness, but if a woman that I don't know particularly well changes her hairstyle, sometimes I get confused.
Like my wife will be watching her housewife shows and I'll be like, "Who's this lady? She's new."
And my wife will be like, "That's the same woman. She changed her hair for the talking head segment."
Anyway, the prince wasn't the one going around looking for her. He had people for that, which is why they needed the slipper.