Originally Posted by hummingway
It was during the "dark ages" when knowledge of water
sanitation seemed to be lost
The dark ages are generally understood to refer the Early Middle Ages, which followed the decline of the Western Roman Empire, between about 500 and 1000 AD.
Due to disease, a good percentage of the population didn't live to be five years old, and the average life span was only about 30 years for a serf or a little longer for a noble. If you survived your first 5 years, you could then expect to live past your early forties.
What they did might not be our best example.