One of my hunches is that people differ much more than commonly thought on the accuracy and strength of face recognition, even outside of clinical prosopagnosia.

I'm very poor at this, tending both to not recognize people, but also to over-recognize; some days every stranger I cross makes me think of someone I know strongly enough that I almost break into a smile and start greeting them, and because of past embarrassing occasions I've developed compensations which now manifest as shyness.

I'm very bad at recognizing celebrities; I've often been out walking with my wife or with friends, and hear "Oh look, here goes X" where X is someone I saw too much of on TV. And I've totally missed them going by, and a second glance leaves me unconvinced it's actually X.