[throwaway4aday]

Back in the day people made tea out of anything they could get their hands on that wasn't outright poisonous. https://en.wikipedia.org/wiki/Herbal_tea#Varieties

Also, if you're in constant pain you'll try all kinds of random stuff to make the pain go away. If necessity is the mother of invention then desperation is its father.

[hinkley]

Tea and beer are pathogen-depleted and so it makes a ton of sense that they were both imbibed 'to excess'.

History of the World in Six Glasses claims that tea and coffee more or less caused the enlightenment. One, it stopped day drinking by the intellectual class. And two, they were foil for socialization.