Actually the modern concept of a school was developed to train people for industrial jobs, where they would have to follow instructions and a schedule set by their superiors -- hence the strict scheduling, the rank-and-file arrangement of classrooms, and so forth. Prior to the industrial revolution most children did not go to a formal schools, and would receive their education from parents and tutors, or by some other ad-hoc arrangements. In some parts of the world it was common for traveling teachers to board with a family for some time and educate the children.