It may be your subconscious that's the genius. Where do those ideas that pop into our heads come from? Meaning the ones that are not at the end of a train of thought. Having more than one mind in our heads seems a more likely cause than a god. If our minds are the end result of billions of years of evolution, why shouldn't there be more than one?

Personally though, I don't think a genius would be forever changing things. They'd get it right the first time.