Pokémon: the Journey from Muji to Sun and Moon

The soul of an adult was stuffed into the body of a 10-year-old child. The first thing he saw when he woke up was the morning light in a new town. His name is Jim Parker. On the outside he is an ordinary traveling boy, but on the inside he is a ruthless and calculating adult. He doesn't compete in Pokémon Masters, he doesn't save the world, he doesn't do what a hot-blooded boy should do. He just followed Xiaozhi, watching the idiot stumble along the way, treating every Pokémon as a friend, and making every journey a legend. Then he discovered that this journey, which was supposed to be just a foil, gave him what he wanted most in his life. Give your youth an explanation.