Environment is the invisible hand that shapes human behavior. We tend to believe our habits are a product of our motivation, talent, and effort. Certainly, these qualities matter. But the surprising thing is, especially over a long time period, your personal characteristics tend to get overpowered by your environment.
His example of the spread of agriculture is ok, in my opinion, but I do agree with his primary point that environment plays a huge role in your success/productivity/etc.
If you can shape your environment to help yourself succeed your chances are that much better.