>>13888237Basically this. The only person in recent history who could have claimed to have extraordinary noteworthy intelligence was Stephen Hawking, but that was partially due to his condition. If your brain no longer bothered wondering about taking care of yourself in any capacity, nor doing anything other than thinking and writing/speaking, you'd end up a lot smarter, too.
There are manifold persons in the world who have the capacity for untold brilliance, who will never know because they are in a daily struggle for survival that takes all of their mental ability to overcome. Only people who have a lot of idle time have the luxury to apply their intelligence to scientific or scholarly ends.