Because socialization is utterly and fundamentally critical to human development. We may not need to be with each other 8 hours a day, but that bit is a matter

Because socialization is utterly and fundamentally critical to human development. We may not need to be with each other 8 hours a day, but that bit is a matter of pragmatism. FYI you are not 'forced'. If your parents want you to stay at home, they can do that. If they want the state to provide your education, it's 30 to a room. And of course, you can pay $50K/year to have 5 per class private school.