Having taught himself more about the sciences than any teacher of his age already knew, Leonardo Da Vinci is a quintessential autodidacts.

Autodidact (plural: autodidacts)

n. A self-taught person; an automath.

We’re back! The High Vocabulary Word of the Day is starting a new year with 365 words, including a reformatting of some old ones.

Examples:

When it came to formal classes, I was a slacker. But I’ve always been a diligent autodidact and can teach myself virtually any subject — if I have a serious interest in it.
— Dean Koontz, “Q&A” column, Dean Koontz: The Official Website (16 June 2006)

He was the perfect autodidact. He wanted to know it all.
— Gore Vidal, “Edmund Wilson: This Critic and This Gin and These Shoes“, The New York Review of Books (1980-09-25)

I’ve also incorporated into my autodidacticism a distrust of schools as inefficient, repressive institutions. It’s part of my new “damn the man” persona!
— T. Rex, Dinosaur Comics

Public-library intellectuals, magpies of knowledge, like most autodidacts we were incapable of evaluating our sources.
— Edmund White, “My Women,” ‘The New Yorker‘ (2005-06-06)

Etymology

• From Greek autodidaktos: auto- + didaktos (taught).