It is just because civilization is ever evolving, changing, and becoming more complicated, that experts find it so difficult to define it in explicit terms.
“So, there's like one luxury you take and since we do that, y'know, you're involved with people in suits; business people all the time. But hey, if I sit down on a bar and they leave, good for me.”
“Hollywood... was the place where the United States perpetrated itself as a universal dream and put the dream into mass production.”