New ideas are always built on existing notions. Same with science fiction or any inventions. Nothing gets created out of nothing. Yes it is simple, because that's reality.

Imagine you are completely blind. The concept of colours would exist in your mind because you have access to literature mentioning it. You would know it's a thing, it exist, and yet, because you haven't been exposed to colors, you would have no memories of them of your own.

Now imagine if everybody in society was blind. Because nobody would have been exposed to colours, there would be no memories of them. It wouldn't be a thing as an idea in people's mind. As a result, there would be no way of thinking about the color red, or blue. It wouldn't be part of language either. Why describe something that we don't know that exist?