Even in cities that happens, depending on the city and your lifestyle. I live in a city of 500,000 people (1.5m metro area), but I recognize people all the time, because we don't spread out randomly throughout the city on a given day. For example for groceries, I almost always shop at the three grocery stores on my street, because there's no particular reason for me to carry groceries across the city when I can just walk next door. There, I see mostly other people from the neighborhood and recognize most of the employees. I usually recognize people at coffee shops and bars where I'm a semi-regular, too. Fairly often I'll even run into people I know just out on the street or metro and stop to chat.