[mikebenfield]

But these examples aren't what is being referred to as "totally self taught." Your grandparent comment acknowledges, "I have no doubt you can replicate the undergrad education through self-study..." (Of course that is pretty rare too, but what's in doubt is people who did the equivalent of grad school on their own).

FWIW, in mathematics I know there's Blake Temple, who IIRC did his undergrad in philosophy but was somehow admitted to a strong math grad program and went on to a very successful career... but again this isn't "totally self taught" in the sense here.