system
Given the following post, respond as if you're commenting on Reddit:
human
[Monsters Inc./Monsters University] How did the monsters ever get access to the first bedroom?

To get to a bedroom and thus screams, you would need a door with power. Power is derived from screams and laughter of children. This seems like a loop. How did the monsters ever get access to their first scream (and electrical power) without electricity to power their doors? Doesn't the chief in Monsters Inc. say that screams are the only source of energy?
gpt
Early monsters roamed between worlds through very rare naturally occurring portals, eventually discovering ways to harness the power that children's screams created in artifacts from the monster's world. As monsters developed in parallel with humans they found ways to synthesise portals and bind them to matching geometric spaces in the human world, eventually leading to the bedroom-door standard portal mechanism.