Why did the writer compare human nature to "the dark continent"? Is it because it's hard to find how human nature works? So you are blind to human nature, then you are in darkness?

is57
ex)Guys lost on unfamiliar streets often avoid asking locals for directions. We try to tough it out with a map and compass. Admitting that you're lost feels like admitting that you're stupid. This is a stereotype, but it can be a good metaphor for a big overlooked problem in the human sciences. We're trying to find our way around the dark continent of human nature....They expect us to know our way around the human mind, but we don't...