from https://en.wikipedia.org/wiki/Albert_Einstein
Einstein excelled at math and physics from a young age, reaching a mathematical level years ahead of his peers. The 12-year-old Einstein taught himself algebra and Euclidean geometry over a single summer.[28] Einstein also independently discovered his own original proof of the Pythagorean theorem aged 12.[29] A family tutor Max Talmud says that after he had given the 12-year-old Einstein a geometry textbook, after a short time "[Einstein] had worked through the whole book. He thereupon devoted himself to higher mathematics ... Soon the flight of his mathematical genius was so high I could not follow."[30] His passion for geometry and algebra led the 12-year-old to become convinced that nature could be understood as a "mathematical structure".[30] Einstein started teaching himself calculus at 12, and as a 14-year-old he says he had "mastered integral and differential calculus".[31]
At the age of 13, when he had become more seriously interested in philosophy (and music),[32] Einstein was introduced to Kant's Critique of Pure Reason. Kant became his favorite philosopher, his tutor stating: "At the time he was still a child, only thirteen years old, yet Kant's works, incomprehensible to ordinary mortals, seemed to be clear to him."[30]
