Every living organism is fulfilled when it follows the right path for its own nature.
We are all individuals. I can't eat for you and you can't eat for me. I can't sleep for you and you can sleep for me. We are absolutely all individuals. When our purpose is fulfilled, it feels beautiful. That is, to me, the feeling of fulfillment.
My mom was a screenwriter. I saw a lot of people who didn't seem very fulfilled creatively or otherwise by their roles in the motion picture industry.