[wrinklytidbits]

It could be that it was perhaps a delicacy to eat cat feces: perhaps it was due to a cat's carnivorous diet, and it could be that one day a cat feces eating guy or gal got a good buzz and made the discovery that that cat had been eating a certain berry. Chasing the buzz they figured out coffee.

[Someone]

My bet would be on famine, a kid, or both.

Alternatively, if you encounter the cat’s faeces after it got dispersed a bit, it may take a while before you realize that the nicer tasting coffee beans you find went through a cat.