The Kokiri are most comfortable in the forest. Being as attuned to the trees as them meant they were very well versed at survival away from civilization. Link was no exception.
Link's survival skills were as good as any other Kokiri's. He knew how to build a fire, tell time, clean water, figure out his compass directions, identify certain edible or medicinal plants, track, hunt, and clean animals, and he was well versed in constructing simple lean-to shelters.
In other words, Link was exactly the right kind of person to get lost in the woods with. What a coincidence it was that he happened to be lost right now.
Link felt a blush invade his cheeks. He always prided himself on his sense of direction. Even when he left the Kokiri Forest for the first time, he did not get lost. The fields of Hyrule were not exactly well travelled. People tended to just move to towns and then stay there until they started pushing up daisies. Travel wasn't exactly huge, which meant paths and signs were not necessary. Even the fields of Termina gave him no trouble in terms of navigation. Maybe Link could be a navigator on a ship when he grew up?
Each step deeper into the woods awed Link. The magic was completely different here. He could not hear the soul of the forest, nor did he see hide or hair of a skull kid, deku scrub, or even a stalfos. The plant life, though largely the same as in the woods he knew and loved, began to see some additions in new flowers he had never seen before, as well as some seemingly alien fungi. Link did his best to give all the unfamiliar life a wide berth. It was survival rule number one for the Kokiri: If you don't know what it is, stay away from it.
Link was honoring that rule like the alien life around him was the plague. It meant much of the life around him could not be admired but with his eyes and ears. This was fine, though. Link did not ask for much. The trees gave him comfort.
The trees brought him happiness. They were familiar. They would not up and leave. Even Ganondorf could not outright destroy the lost woods. They were constant.
Link grew to love constants in his life. He sometimes longed for the days before he set out to fulfill his destiny. He was the boy without a fairy. He was ridiculed by many of the Kokiri and ostricized. He had few friends, but he rarely let his lot in life discourage him. When he was sad, he would force himself to go out. When he was bullied he would stand up for himself. He knew Saria had his back and wanted the best for him too, even if he was a little bit different.
Then, Navi came. And his whole life was flipped on its head. It isn't every morning a small child is woken up by the fairy he never had and told that he will save the world from a great evil. Link found it amazing that he so easily drew the hero stick, yet could never win the lottery in Termina.
He remembered that, at first, Navi did not particularly like him. If anything, she intitially disliked him, and was not above light teasing or refusing small talk with him. As the journey progressed, however, and the dangers grew, they would begin to bond.
Link would never forget the immense, almost motherly worry he noted in Navi's voice during his first encounter with the redeads. He would never forget how relieved she was to see him open his eyes again. Link would never forget falling asleep with the fairy close by, and he would never forget telling her that he loved her for the first time.
Navi took away the loneliness Link was not aware he suffered. It was thanks to her that Link was no longer the boy without the fairy. Link was happy when he had her, even if they fought from time to time. It made him wonder what the rest of his life would be like, if he could spend it with her. Those were the days he was the most impatient. How desperately he wished to end his adventure so he could spend his time with her!
As the saying goes, however, one should be careful what he or she wishes for.
They had done the final thing asked of them by Princess Zelda when Link had returned the Master Sword to its pedestal and shut the Door of Time. Upon closing it, however, Navi hesitated. For an instant she began to shine brighter than Link had seen her shine before.
"Navi?" was all he asked. The fairy, though he could not see her face, appeared both panicked and resigned. She turned to a window in the Temple of Time, where the sun was shining the strongest. Without another word, she flew towards it.
Link was silent. It wasn't Navi's departure that resulted in his so rarely speaking, mind you. Link was always a very quiet person. Even when they travelled, Navi was the one who engaged most conversations, not Link. When he did, it was little more than awkward small talk that would die out quickly.
He did not shriek, he did not cry, he did not stomp his feet, and he did not yell. Instead, he squinted his eyes, attempting to make out Navi's shape. Alas, he was unable to. The glow of magic around a fairy often rendered their true bodies invisible to the human eye. That combined with the sun did not help matters. Link assumed she simply left through the open window for reasons unknown.
He stared at the window until his eyes were forced shut, and he remained in the Temple of Time in that same position until the sun fell to the horizon. Like it or not, he still needed to go home. Alone.
Again.
It was then that Link realized what he had been doing. His hands were balled into fists so tight that his nails dug into his palms and drew blood. Where did she go? Why did she go? Why without a word? Did he do something to offend her? Perhaps he didn't thank her for her help soon enough? All he knew was his fairy companion throughout his journey was missing, and now he wanted only to find her.
That was why he went to Termina in the first place, much like it was why he searched the woods now. He just wanted to have his companion back. He wanted his family back. He wanted home. He wanted to be a child again and have the childhood he was denied. If only he remembered how to be a child in the first place.
As the saying goes, however, one should be careful what he or she wishes for.