Maybe it's what the kid wanted to do and what the parents thought was best as well. Maybe some kids like talking about things that older kids are learning about. Then where would they fit in better? In a classroom of students with common interests and talent, or in a classroom based on their Chinese Zodiac sign?
There is the quiestion of what to do when they graduate but are still too young to work. Travel? Video games? Can't drive to the mall. Oh well, everyone's life is complicated. That's life.

Youth lives by personality, age lives by calculation. -- Aristotle on a calendar