I don't know. It seems to be as random as people coming or leaving this place. I doubt anyone even remembers what happened before they woke up at the base or at mom's house.

[Except in their own worlds, but well, that was obvious.]

I'll also be honest... and say that when I was in the team, I stole a few Pokémon. Definitely not because I wanted to and I felt guilty for each one. I just didn't have much of a choice. I needed to stay on their good side, because I needed information from them. So I could deliver it for people on the outside.