Have I Seen You Before?

When I go to a new place or when I return to a place I haven't been in a long time, sometimes I see faces that look kind of similar to faces that I had seen in the past. When I mean a new place, I don't mean a place you just see once, but when you are regularly living or present in a certain place, like when I went to high school (I went to a private high school instead of a public high school, so everyone was new to me) or when I went to college. I just remembered about this kind of feeling when one of my friends at home said that someone we had just passed looked like someone he knew from college. I wonder if other people feel the same way too, because my friend said he also felt that way.