<I>I would say that it would be more obvious if you aren't looking for similar looks</I>

A lot of people see what they expect to see. I'm adopted, but when I was younger, people were always telling me how much I looked like my (adoptive) mom. It used to be a joke between us, because we really looked nothing alike. On the other hand, once my friends found out I was adopted, they would walk down the street with me and see all kinds of people who looked "just like me" and comment "maybe that's your real Dad". I never saw much resemblence.