Grand anthropoligical question. Fertile Crescent - It all started about 10,000 years ago when we switched from being subsistence-cultures to production-based. The "new" agriculture got people off their hunting, gathering, and wandering ways and decided that settling down and having farms was better. Certainly it was for those making decisions and not doing the work for it created economic classes where decision-makers weren't required to produce anymore.
Surpluses, growth, and expendible incomes have their price. We are more "secure" now, but our culture holds that unless you're working till you die that you're not doing your job. Our technological tools that could make our lives easier don't - instead they just raise the bar of expectation.
Which, of course, leaves us with great toys and no time to enjoy them.