Hello. Actually that's not what he meant. It's not even his quote. I read his book. What he was trying to say was that the subjects taught were exercises for your mind. Even if you dont remember what you've learned, your mind is more "fit" . People who are stuck in their way of thinking come at all levels; it has nothing to do with intelligence. Your example with pluto is why there are newspapers, scientific journals, new editions of books, television, etc. Hope that helps =)