Hello I was thinking, in the world in general, there are many people who would actually prefer to do hard labor over mind stimulating work. Even in my own studying I often get pain in the head and frustration. It doesn't take (relatively) too much thinking to get me to get up and take a five minute break. Many concepts in math and science just hurt the head to try and understand. Do you think humans have a higher threshold of pain tolerance for their muscles over their brain, where it would be less painful to do a full day of manual labor over a full day of equally intense studying? I know this is a biased audience with many brilliant people, but for me learning these "elementary" concepts prove to be very challenging and frustrating.