How Open is You Mind?

So yesterday I went to hear former Secretary of State Madeleine Albright give a lecture and answer some questions at the Carnegie Music Hall of Oakland in Pittsburgh PA. There was something she said, among others, that certainly got people's attention. She said, "The only completely open mind is an empty mind". There is of course the very simple idea behind this that no matter how much we may try to open ourselves to things, take in different perspectives and try new things we will always have the things that have shaped us. It is true that everyone has a different background, a different perspective, and different emotional responses to things. To be completely open we would have not to have taken in anything. So now my question is just how open to we really want to be? We hear people say, "keep an open mind" and "my mind is always open to new things" but at what point should yes be yes and no be no?