In the early 1700's, a french math teacher named Jean-Baptiste Clairaut had 20 children. He taught all of them to read using Euclid's "Elements". Unfortunately only one son, Alexis Clairaut survived to adulthood. By the age of 9 he had mastered Guisnee's "Applications of Algebra and Geometry" which provided an introduction to differential and integral calculus and analytical geometry. He and his younger brother both read their first papers to the Paris Academy of Sciences by age 13 and 14, respectively. His brother died at 16 years of age. Alexis Clairaut was of the same calibre as Sir Isaac Newton, and reproduced his work.

What you learn by age 5 stays with you the rest of your life. Unfortunately, there are so many people in the world who are dragged by the ear to religious classes on a regular basis, taught history, ethics, language, how to think, using the Bible, the Quran, or whatever. Science is easy if you understand math. And I've never met anyone who learned to read using a math textbook. Most parents would be horrified. But it has been done. And it worked. Twice. Medical science could have made it work 20 times for the same family. They were born 250 years prematurely.