This changed with the emergence of “Patient 31.”

Reuters’ coverage of the “Korean clusters” provided the world with a vivid glimpse of the volatility of COVID-19. One person showed poor judgement, and in turn caused cascading catastrophe in her communities.

Events like the COVID-19 pandemic are thankfully rare. Moments like these—when a lot happens all at once, and the experience is shared by a collective—shape future history like nothing else. We are learning a lot from this. Not only are epidemiologists now a famous profession, but we’re all learning exactly what it takes to provide good healthcare, what good governance looks like, how public health is community health, and more.

Patient 31 holds a simple lesson for systemics: the fragility of apparently solid social systems. South Korea seemed to do everything right. Yet, due to the volatile nature of this particular socio-health system, a single “free radical” caused immense damage.

Similar volatility is evident—but more subtle—in other social systems. Consider how memes spread. Our massive communities may seem immovable at times, but it’s clear that the wrong (or right) phenomena can spread rapidly and deeply.

Stay safe.