People are complex creatures. They needed motivation and the right geographical and climatic conditions to become farmers.
Motivation? We don't really know. Probably some women figured out that it would be easier to plant seeds than to find wild plants. Maybe they saw the possibilities of settling down rather than moving around hunting and gathering.
Geographic features? Rivers that provided water and the rich silt brought be flooding helped people turn to farming.
Climate? They needed a long enough growing season to bring crops to maturity.
I think every group of people at any time throughout history depends upon a few intelligent and innovative leaders to make changes in their lives.