You were the only one who preferred to work alone as a Trainer instead of in a team. This worried all of the regions, it was dangerous to work alone. Especially if you're not in a team

One day, a familiar black haired boy named Ash with his partner on his shoulder, who was Pikachu, decided to challenge you to a Pokémon battle, you hesitated at first but then accepted afterwards

After the battle was over, Ash decided to ask you a question

Ash: "Hey. I know we just met in all but would you like to join my team?"

He gestured towards Goh, Serena, Flannery, Hapu, etc. This made you pause, you never trusted anyone enough to join their team