Going out costs a lot (of water)
A lot of water is necessary to manufacture “things,” such as the shirt you are wearing.
That shirt? About 700 gallons. How much water does it take to make a hamburger? Try 4,000 to 18,000 gallons for one thick, juicy hamburger.
How much water would you carry to eat one hamburger?
(p. 47, Water Runs Through This Book)