If your best friend was walking down a busy street towards you, you’d be able to spot them and pick them out of the sea of faces really quickly. It’s not that you don’t identify any other people, it’s just that your mind recognizes that you’ve had past interactions with them. It has a reference point. It found them in the database. Your mind is really good at this and does it so fast, you don’t even consciously notice it. But it’s a totally passive activity. You don’t go, “I’m going to keep track how many cars I see that are like mine”. Or, “I’m going to look for my friend Bob in this crowd of people.”