Anthropologist Ralph Linton made the remark, "The last thing a fish would ever notice would be water." How does the meaning of this statement relate to the understanding of culture?

What we're surrounded by, we're used to. The things that happen in our culture are taken as the norm, while immoral things might be happening right in front of us without our knowing. When slavery was the norm, many people (who if alive today would probably agree with modern logic) saw no problem with it. We don't even recognize most aspects of our culture, and our eyes are only opened when we come into contact with a different culture