This takes place eight years after Dragon Ball Z - it's my take on what would happen in Goku's absence with Uub.
Piccolo's heart stopped for a brief second as his green ears twitched, sensitive to his surroundings. He clenched his fist and lets his intertwined legs fall, hovering just feet above the smooth alabaster of Kami's Lookout. Readjusting the turbin perched on his head, he resumed his meditative position and concentrated once more, the wrinkles on his forehead furrowing in thought.
He swore that he had just heard a familiar laugh approaching for the first time in years, but it had to have been a fluke. It was impossible that he was back - he had been expected years ago, but it was impossible all the same. Piccolo's breathing shallowed as he listened once more, receiving the same results. It had to be true. He was back.
Piccolo descended gently until his golden slippers touched ground. Mr. Popo looked curiously at the Namekian until he spotted the grim expression on his face. "What's wrong, Piccolo?" the genie inquired, pushing his hand against the stony ground to help himself out of the flower bed.
With a grimace on his sharp features, Piccolo muttered darkly, "Goku's back."
Goku stretched his arms out, his blue shirt catching the wind beneath him. He laughed lightly as he twisted his body through the air. He couldn't believe it; he was heading back home.
Almost eight years had passed since he'd even been on this side of the world. Time hadn't changed a thing in his memory, though, which comforted him. Everything seemed just as it had been back then. He couldn't wait to see Goten, Gohan, and Pan to see how much they'd grown; he would even put up with Chi-Chi's nagging to see her again. It had been too long since he'd been home, and he knew his family would be as happy to see him as he was them. There was no doubt about it.
He stared at the shining ocean below him, stretching beyond his line of vision. It was definitely good to get out of that village. Uub had become stronger within that decade of training, as had Goku. It didn't feel as if that much time had passed, though. There were no memories that stood out during that time, as if it had all been wasted. The village was in better condition than he had found it in, but other than a few rescues, Goku wasn't satisfied. After saving the world so many times, there was little that could compare. It felt as if he hadn't done anything to help humanity.
Putting those humbling thoughts aside, he grinned once more, his heart pounding against his chest. He really hoped his family would be happy to see him. His leaving had been abrupt, but it was necessary. It was only once in a lifetime that somebody could train with a partner that contained so much potential. His mind drifted quickly from his family to his friends. He hoped Krillin was keeping up in his training - even after growing hair on his head, he couldn't abandon his passion for fighting. He hoped that Yamcha and Tien and Chiaotzu had kept up with their training as well. After fighting Uub for years, competition was sure to spring up.
Piccolo, he was certain, was training constantly; it was as much in his blood as it was in a Saiyan's. And as for Vegeta and Bulma and their children - they were hopefully the same as always, too stubborn for their own good. He smiled peacefully with thoughts that Vegeta was probably still trying to best him, which he knew would never happen. It was impossible; Vegeta, even with royal blood in him, would always be second to the low-class scum.
Goku drifted along peacefully, anxious to arrive now. He hoped he hadn't missed much, but eight years was a long time...
After spotting Mount Paozu in the distance, Goku sped up. It looked just as it had, so many years ago... The welcoming domed house greeted him as he landed firmly on the pathway leading up to it. He stood there for a moment, inhaling the scents from so long ago. It tortured him to just stand there, so close to friends and family, but he resisted for a moment longer to compose himself. This was going to be more difficult than he had anticipated earlier, but he couldn't turn back now. The fearless Goku had stood up to so much - now he could stand up to his family.
He marched with determination towards the house, barely containing his excitement. Once in front of the door, he gulped and cupped his hand to his mouth, yelling, "Chi-Chi, I'm home!" His voice was hoarse from nerves, but he was certain Chi-Chi would recognize him. She had to.
However, nobody answered the door. He glanced around cautiously, taking in the details of his surroundings for the first time. There was a new car in the driveway, a newer model of the one that he had driven so long ago. The hedges were trimmed, and the grass was cut. Nothing seemed particularly out of place to him.
Goku placed his fingers over the doorknob as he focused, trying to locate any power levels from within the house. There were none to detect, though, so he turned the knob and pushed the red door open.
He stared around the dark entryway, noting all of the similarities from years ago. The same old sofa in the living room, the same cushions, the same paint color, the same tables. He approached a chest of drawers that Chi-Chi had bought years ago, picking up one of the iron-wrought picture frames sitting upon it. It contained a portrait of Goten, a young adult by this time. He examined the features that seemed so similar to his own before setting it down, wandering towards the kitchen.
His stomach growled with a thunderous roar as he spotted the refrigerator, placing a hint of a smirk on his face. He approached the fridge with his hand on his stomach, opening it without any doubts. Surely Chi-Chi wouldn't mind. After clearing the fridge of its contents, Goku exited the house. He felt uncertain of where to head next, so he decided that Capsule Corp would be his best bet in finding somebody. Everybody congregated there due to its size and beautiful gardens - there would surely be somebody he knew there.
Before he could even take off, though, he felt a large energy level approach him. Strange... He paused, waiting to see if it was coming for him. Then, in the distance, he could make out the familiar green complexion of a certain Namekian hiding under layers of clothing. Gohan's first friend had arrived... Piccolo.