Okay here is my idea, I know its wrong and makes no sense and that I have not done the extensive Zelda Research that most of you have done. So here it is. Most every Zelda game has a totally different plot, different towns, and different characters. All of the games take place in different times and possibly different dimensions. But they all have the following, Zelda, Link, some form of the Triforce, and an evil god-like being like Ganon. In Oot is says that the godesses created Hyrule and the Triforce which also created the Sacred Realm. After the godesses left the Trifore's power transformed something into an evil force of death and a hero rises up to save the day like always. Perhaps the godesses learned of the evil in the land and created a hero, Link, to save the day. This would explain why Link is always young and not older. This is just my idea, I dont know if this is right, I am just posting it because I want to.