Any and all creativity...comes from the same place.
You just try to get out of your own way and let it happen.
(Thank you Marty)
Blessed are they who step aside and let creation do its job.
There are moments in every artist's life when the work seems to do itself. I've noticed this in painting. Sometimes the brush just seems to know where it's going without me exercising any will power over it. And it has been even more apparent in my acting career. I can recall those moments that every actor hopes for, when the character seems to play itself. Some magical thing happens when something takes charge of my mind, my voice and my body and I'm just an observer.
For a lazy actor it may happen once or twice in a year's worth of performing. For a disciplined actor it will happen much more often. All the reading, table time, rehearsal time and home work the actor puts in prepares him for those moments. For a genius it may happen once a week.
There's a famous story, probably true, about Lawrence Olivier who had just given one of those inspired performances. It was so brilliant that many of the other actors were waiting for him when he came off stage in order to congratulate him. But he was in a fit of fury. When asked how he could be so upset after such an unusually magical performance, he said it was because he couldn't remember what he did.
DB Vagabond Journeys