Why did children not need formal schools for a long while?

There was once a time along time ago when children had a different way of life. They didn’t need to attend schools because they could learn everything from the school of experience. The experience of their daily lives gave them enough education to survive during that less complex period.
     School was not necessary for them to learn other skills because their parents would teach them all they needed to know about capturing their food and tilling the earth. Learning the basic survival skills of how to feed themselves and grow food was the only thing most people needed to learn during that time period. Slowly, however, life became more complex, and people found the need to communicate with people in distant places. The world was expanding, and people needed to interact with people outside of their little town or village for business or for personal reasons. Then, it became important that children learn to read and write. When money became the form of buying and selling, they needed to learn how to count and calculate. These things were fundamental for children to know in order to survive in this more complicated world. And because these skills could not be learned from first-hand experience, school became necessary to teach these skills.