We certainly have memory, and can forget people, like a random person we were once shown a picture of. And pictures are not 3D faces either.

But if you meet someone for half an hour and then run into them later that day, you recognize them just as easily as you do your mother. There's zero doubt that they are the person you met earlier (unless you have face blindness or something). You don't have to meet them for 10 more hours to be able to recognize them instantly.

Sure you might forget them a year later but that has nothing to do with your recognition capabilities, but with memory.