Obviously any fiction is going to be a combination of what is invented, what is overheard, what is experienced, what is experienced by people close to you, what you are told, what you have read, all mixed together into this kind of soup which, like any good soup, at the end you cannot really disting
There are times when the writers ask us to improvise. Sometimes the animators are inspired by what you do, and sometimes you are inspired by what the animators do.