Humans needed water or they would die, but dirty water killed as surely as thirst. You had to boil it before you drank it. This culture around tea was a way of tiptoeing along the knife edge between those two ways of dying.
Neal StephensonEarly on, I settled on the first-person strategy as a way to deal with exposition and world-description issues. As long as the book is, it could have been far longer had I gone with an omniscient third-person narrator, or multiple point-of-view characters, since either of those would have enabled me to impart much more detailed information about the history and geography of the world.
Neal StephensonThe hour of noon has passed,' said Judge Fang. 'Let us go and get some Kentucky Fried Chicken.
Neal Stephenson