Who's to say what's normal?

Normality differs from person to person. What I believe is normal, someone else may not. No one can classify exactly what normal is, because no one really knows what it is. I don't believe that there is one "normal" person out there. We all have our differences, our own quirks. To us these things are "normal", but to someone else they are abnormal. We see someone acting a certain way and say that it's not normal. How can we say that? When we are not normal ourself. No one is normal, therefore no one can say what is and isn't normal.