Disciple of experience
Leonardo da Vinci, disscepolo della sperientia. Leonardo do Vinci, disciple of experience. (signed in one of his notebooks)
was self-taught. He learned a little math from an "abacus school" — a trade school for merchants — but other than that had no formal education. He learned through observation, driven by curiousity.
He had some blistering rants for people who dismissed him because of his lack of academic credentials. Imagine criticizing Leonardo da Vinci for his lack of education.