Final answer:
The motivation behind a documentary about a goldfish would depend on the specific theme or purpose of the documentary.
Step-by-step explanation:
The motivation behind a documentary about a goldfish would depend on the specific theme or purpose of the documentary. Some possible motivations could include highlighting the unique abilities of goldfish, exploring their natural habitat and behavior, or discussing the challenges they face in captivity. The content and message of the documentary would determine the motivation behind it.