[gliese1337]

Someone like Feynman is capable of inventing a new language for parallel computing and correctly simulating its execution by hand.

That's a much more impressive skill than just learning another language.

[AceJohnny2]

I don't think so. He didn't invent a new language, but extended an existing one. And I simulate what a program does in my head all the time when debugging (including multithreaded stuff, but I agree that's hard).