My daughter wrote a report on video game development when she was in 5th or 6th grade. Through some connections we got an invite to go to Double Fine studios and have a sit down with Tim Schaefer. He is exactly what you would hope. Nicest guy in the world, absolutely loves what he does and loves talking about it. He gave my daughter a tour of the place, showed her how they thought about designing games, talked her ear off for more than an hour, gave her some keepsakes (design documents from some games they had shipped).
For Psychonauts 1, to really get inside the characters heads, they created their own fake internal Facebook-type site and play acted how all the characters would interact on social media.
Homer: "Reverse Psychology? Oh that sounds too complicated."
Homer's Brain: "Fine. DON'T use reverse psychology."
Homer: "OK I WILL!!"