Princess Zelda sends Link back to his own time at the end of Zelda: Ocarina of Time for good reasons. Although only one of the reasons is directly referred to in-game by the Princess herself after the final Ganon boss fight, players can infer the other reason that Link was sent back seven years from the post-credit scene.
Zelda: Ocarina of Time released in November 1998 on the Nintendo 64, and this classic action-adventure game is rightfully considered a masterpiece. The game is unique in that its soundtrack and gameplay are intrinsically connected. From Bolero of Fire to Song of Time - the tune Zelda uses at the end to send Link back to his life before the events of the game unfold - the songs of Zelda: Ocarina of Time are recognizable by fans years later.
Zelda sends Link back in time so that he can warn the child version of herself about events that transpired in the timeline of Zelda: Ocarina of Time and prevent them from happening. This causes the timeline to split into three (the Child Era, Adult Era, and the Fallen Hero timeline). Furthermore, rather than leave Link in her timeline, which would mean Link never gets those seven years of his childhood back from when he was in stasis in the Sacred Realm, Zelda chooses to let her friend go and live his childhood as it should have been.
Princess Zelda Uses The Ocarina Of Time To Undo Past Mistakes
After the final fight in Zelda: Ocarina of Time, when Ganon is defeated and sealed inside the Evil Realm, Princess Zelda tells Link that it was her fault Ganondorf laid his hands on the Triforce, causing it to reject him and split into the three pieces that then latched onto him, Link, and herself. By sending Link on the quest to unseal the Sacred Realm, she inadvertently led Ganondorf straight to it, culminating in the ill-fated destinies of the various peoples across Hyrule. She instructs Link to return the Master Sword to its pedestal in the Temple of Time and close the road between times, which would seal the Sacred Realm once more. She also directly tells Link to "regain your lost time".
"All the tragedy that has befallen Hyrule was my doing... I was so young, I could not comprehend the consequences of trying to control the Sacred Realm. I dragged you into it, too. Now it is time for me to make up for my mistakes... Now, go home Link. Regain your lost time! Home...where you are supposed to be... the way you are supposed to be..."
After the credits roll, Link is a child again in the Temple of Time. Then the scene changes to the Castle courtyard, and Zelda meets Link for the first time (again). This is, presumably, when The Legend of Zelda's split timelines are created, as Link warns her against trying to get the Triforce (by using the Spiritual Stones to unseal the door to the Master Sword) before Ganondorf does, thus altering events.
While there is confusion surrounding how Link could have sealed the Temple of Time behind him on his return without the Ocarina of Time, and how he still has the Goron bracelet (a relic that was, from that point, from an alternate timeline), there is little doubt concerning Princess Zelda's motives in returning him to seven years prior in Zelda: Ocarina of Time.
