10,000 years ago, in ancient Sumer and Mesopotamia, gatherers discovered, probably quite by accident, that barley left in a container in the rain for a few days would begin to ferment into alcohol – and beer was born. Evidence of ancient beer predates barley bread by 3,000 years.
The desire for more beer is the likely motivation for the domestication of barley and the end of hunter-gathering. Because hunting a saber-toothed tiger after a few pints probably did not end well. And the craving for ever more brew, after more than 2 million years of sobriety, required that we give up our nomadic and carefree lifestyle and that we settle in one place and grow as much barley as possible. That shift in mindset then led directly to irrigation, the plow, the wheel, geometry for measuring land, mathematics for accounting, and writing to keep records.