"A fish only discovers its need for water when it is no longer in it. Our own culture is like water to a fish. It sustains us. We live and breathe...

Fish cannot talk to other fish who are out of water because being without water would kill the fish.  Fish have no way of learning about other cultures.  Fish have no adaptation experience in living without water.  Humans, on the other hand, cross cultures all the time.  There are blended families of people from other countries who have married.  Even people of different socioeconomic levels can be in the same family.  While we often do see the world through the lens of our upbringing and culture, it is possible to change our points-of-view.  People move to other countries all the time, sometimes with the intention to experience another culture.  While our own native culture is important to us, people can adapt to their surroundings, unlike a fish, which cannot start breathing air at a moment's notice.