Yes, but we also need soldiers to keep other soldiers from taking the food. And stone keeps and villages with market places to trade food for goods. And better farming techniques to increase our food production. Also, some more advanced machines to allow better food processing and some textiles. We probably need something a little more efficient than water or steam power. And logistics! Definitely need a way to get people and goods from one place to another. At some point, we'll need to organize all this activity better and start to specialize. Maybe there's a better way to track all this stuff than manual ledgers. Wait, we can leverage electricity and simple lever machines (up/down or 0/1 if you will) for tracking this stuff. Perhaps if we connected all these machines together into some kind of a network . . .

I understand how you grow food, but how do you grow service people?