What are economists missing about North Korea?

After reading a recent WSJ article about North Korea, I found myself wondering about something. North Korea is often described as having an economy that is only a small fraction of South Korea's. Yet the country has survived decades of sanctions, isolation, and economic pressure. Does this suggest that outsiders may not fully understand how the North Korean economy functions? I am not arguing that North Korea is prosperous. I am simply curious whether economists believe its resilience is underes