The Great Deku Tree let Link grow up thinking he was a defective Kokiri, instead of letting the poor child know he'd been adopted. It would have saved him a great deal of anxiety growing up if he'd known the truth.

"I've had two adoptive fathers," he said. "One, was the Great Deku Tree, and, he was a father to all the Kokiri. I wish he'd told me a lot sooner that I was not one myself, it would have been easier to fit in if I'd known I was actually a different race. And if they had known."

Link smiled a little. "My new adoptive father is worrywort bookworm." He paused. "Not... not literally. He's human." He had to specify, he realized, having just said his first adoptive father had been a Tree.