Many of history's most celebrated masters were self-taught. We can argue that Darwin, Abraham Lincoln, Benjamin Franklin, and Leonardo Da-Vinci were avid self-teachers. Lincoln learned prose from the Bible and Shakespeare, and he learned logic from books of law. In fact, many of our lauded thinkers are considered self-learners. Bill Gates, Larry Ellison, and Mark Zuckerberg are all college drop-outs. Yet they are among the world’s wealthiest individuals to date.