Foundation and Earth (Foundation, #5)

by Isaac Asimov

as sensitive as my first, and has ten million times the capacity; but whereas my first brain endured for over ten thousand years, the present one is but six hundred years old and is unmistakably senescent. With every memory of twenty thousand years perfectly recorded and with a perfect recall mechanism in place, the brain is filled. There is a rapidly declining ability to reach decisions; an even more rapidly declining ability to test and influence minds at hyperspatial distances. Nor can I design a sixth brain. Further miniaturization will run against the blank wall of the uncertainty principle, and further complexity will but assure decay almost at once.”

Big implications of computational complexity