Here’s my answer.
My brain works like an engine. The base fuel is hydration, just like any other animal’s brain.
Next comes the raw material. That’s the presence of my character wanting to pursue their goals or escape their obligations. It’s also the unconscious wealth of X-Men comics, fantasy novels, colorful anime, and Christopher Nolan movies that have saturated my imagination.
That all goes into my brain, gets pressed under the weight of my own philosophy, cut by my spiritual and political opinions until it becomes an idea.
The speed charges up. Ideas collide. Words fall like rain, drain off my fingers, and pool on the blank page.
It all runs through me at that point. Going as long as my eyes can stand staring at the screen. Or until the brain can stay hydrated. If the ideas stop colliding, I have to stop and load that back up.
Maybe it helps, but I thought I should share that answer widely.