They so often did though, how many massive fires broke out in London before the great fire finally convinced them to stop building overlapping thatched rooves.

Even during The Plague of Justinian scholars wrote about what was essentially ancient social distancing practices, 2000 years ago later we still can't do it properly.

How many times did they have to put up with rat plagues and stinking open cess pits, followed by a big town clean up, and then nothing change in infrastructure or waste management practices, only to do the whole clean up again ....until the Great Stink got to close enough to the windows of parliament that those in power decided maybe they should address the root problem instead of applying bandaids every few years.

(I don't have a history degree so I'm pulling these details out of the memory depths of my dusty documentary viewings, and I'm probably wrong.)