While we are still children, most of us live at home with our parents, more or less peacefully. But as we become teenagers, things change, and we begin to grow apart from our parents. This means we are almost ready to leave the house where we grew up and make a new home of our own.
All humans must do this, but they don't all do it in the same way. If, for instance, you belong to a primitive tribe (原始部落) ，then as you grew up, you'd learn the skills you needed as an adult—how to catch fish, how to keep the house and look after children. You would be ready to marry in your early teens and you would build a house and live near your family in the village.
This seems a very old way of life, but it is what humans have been used to through hundreds of years. And it is what we are still used to in the 21st century, for man hasn't changed in the short time since he became civilized(文明的). But could you leave home and look after yourself during the teen years? Most people would not do very well. Why? Because although man hasn't changed very much, the society he lives in has changed greatly, which means that we have to learn more and more before we are ready to leave our parents' shelter( 居所 ) and live alone.
However, sometimes it is very frustrating to live at parents' home. Parents can be very upset about late nights, criticizing friends and always saying that we are noisy and dirty. But we still need our emotional (情感的) shelter till we finish our studies, and that is why we usually stay in our parents' home until we feel grown up enough to deal with living alone.
