I think it's virtually certain that, if they are indeed top figures in their fields, it's guaranteed that they are deeply involved in their work, and that means

I think it's virtually certain that, if they are indeed top figures in their fields, it's guaranteed that they are deeply involved in their work, and that means their subconscious minds are processing that stuff non-stop. But the subconscious is a funny thing, because it doesn't seem to require "effort" to operate, however you may define that notion. It's the fully conscious, purposeful, organized work that requires "effort" and consumes "energy". Not even sure how to define these things properly, but everyone seems to understand them intuitively. Anyway, to be successful at the highest levels, it seems like you have to be awfully protective of this "energy" thing.