Author: Unknown
Year: Unknown
Termina never existed before Link arrived there. Certainly, Link's adventure in Termina occurred. However, what I'm saying is that Termina, as a place - a country - never existed before Link arrived there. It's a dreamscape - a fantasy - crafted from either Link's or Skull Kid's memories. It's a land with familiar faces because it was crafted from familiar memories. Think Link's Awakening.
Majora's Mask is Hyrulian in originin. We can't confirm this, of course, but we can assume it is so. Skull Kids, as a species, seem to be native to the Lost Woods, which Lie in Hyrule. In addition, Majora's Mask and the Twili's Fused Shadow share similarities. Let's not forget that Majora's Wrath form and Zant share similar fighting styles (break dancing and moon walking).
Link's adventure in Termina is the quest to accept the inevitability of death. Termina sprung forth in turmoil by Majora's designs. The players are introduced to a thriving land on the brink of disaster, all in three repeating days. Everyone Link helps - from the separated loves to the daughter and her cursed father - symbolize growing up. It's the only way Link knows - we're talking about the guy who saved Hyrule, here. Termina sprung out of Link's mind and, for all its beauty and wonder, the message at the center of it all is the impending future of death. Just look at the moon.
Link is screwed. Sorry, but it's the truth. Link isn't a Kokiri, he's Hylian. During his adventures in Ocarina of Time, nothing bad happened to him because he had the protection of a fairy. However, after the game ends, he enters the Lost Woods WITHOUT a fairy. He's doomed to become a stalfos, just as the Potion Shop owner's son did.
"You've met with a terrible fate, haven't you?"
Termina is a land constructed by Majora and, while in this land, Link embarks on a grand quest to save the world from destruction. I'm not saying this didn't happen. It did. Link's a hero. However, Majora created the land itself out of Link's memories and ideas. At the point in time in which he met Majora, what concerns the young Link is the knowledge that he is lost. He knows the forest's legends. He knows what happens to people who get lost in the woods...
The Hero's Shade in Twilight Princess, the game that follows Majora's Mask by around 100 years, claims he was once a hero. Like Link, he is left handed, he can take a wolf's form, and most of the songs used to call him come from Ocarina of Time and Majora's Mask. Oh, and he resembles a Stalfos. He also shares a quote with the Happy Mask Salesman. "Believe in your strengths."
Fierce Deity Link represents adulthood. Think about it. Link's quest up to that point - collecting all the masks and helping everyone in Termina - is traded for the Fierce Deity's Mask. It's symbolic of growing up. The idea of adulthood is important within the game.
Link accepts his fate. When we start the game, we find Link searching for a dear friend. By the end of the game, Tatl hints that Link got what he was after. He came to accept his fate. He grew in his journey and, in his own way, he became a man - an adult.
Oh, by the way, Tingle is the Terminian version of Link.