He had to get out of the cage. [Mild spoilers for Gaiden.]
He had to get out of the cage. There was something he needed to do - someone he needed to see -
But the days and weeks and years went by and whatever he needed to do retreated back behind the fog with the rest of his memories.
"But I never called anyone," Goku says, blinking up at the shape, holding out his hand. "I didn't know anyone to call."
The first voice Goku ever heard was his own, a raspy croak that startled him into waking. He'd been dreaming about the sun - not the stripes of light that came into his cage, but something bright and blinding that took up the entire world.
And the sun had called him -
"Goku," he repeated, the word hurting in his throat.
"You came back," Goku whispers, clinging to Sanzo's robes. "I thought you'd left me behind."
Goku didn't remember anything - not why he was in the cage, or what he did before it. He just - waits. He doesn't know what he's waiting for, but he's not going anywhere, is he?
He thinks, sometimes, that he's waiting for someone. That he's waiting for someone to keep a promise. He tries to remember who promised, or what he was promised, but all he could remember was the sun, bright and gold.
Goku leans forwards one night - Gojyo grumbles and kicks, and Jeep rocks in protest - and resting his head against the back of Sanzo's seat. He curls a hand into Sanzo's shoulder, and mumbles "You should have told me you were coming back."