As Americans we tend to think of common courtesies that might be normal to people in other countries, uncommon for us. The only person that should open a car door for you is the valet. We don't always like to shake hands. We have huggers and non huggers, weak hand shakes, and non verbal ques that we give each other that are often unfriendly to say the least and sometimes the opposite of courteous. We don't understand why people bow, kiss a hand or a cheek, and should not call their elders by their first names. It is what it is! What do you consider courteous and what do you teach your children?