Plato's Allegory of the cave.

The allegory of the cave was an analogy of Plato, the greatest of the ancient philosophers. The allegory of the cave was based on the majority of mankind. We are like prisoners chained in a dark cave. There we live from childhood knowing only the dark cave wit ha blazing fire off to a distance. All that is visible to us is shadows made by one another reflected on to the wall of the cave. …

…Tab/>Maybe someday like the prisoner who became unchained, one will go out into the world and live on his own. When he sees what it's like to be independent, he will tell all of his friends how amazing it feels to finally have space and privacy. Just like the men from Plato's allegory of the cave, still some high school graduates will maintain that they are safer at home with their parents.