His schizophrenia made him believe that God sent him on a mission to create an operating system for him. He had a monomaniacal obsession with programming. I believe he was able to program for fourteen hours straight daily. Even if you had a genius-level IQ, it's unlikely that you'd be able to achieve something as he did, because you'd simply become bored out of your mind. You wouldn't be able to make progress as quickly as he did, even if you'd be able to learn things more quickly than he was able to learn them, because you'd constantly be losing focus out of boredom, and would need to take brakes more frequently. I believe this is the case with most people who have made incredible achievements in STEM. It's a combination of high intelligence with monomania.