You also have many projects that have nothing to do with computer science, such as your musical composition, Fantasia Apocalyptica. You even built your house around a two-story pipe organ. Is this variety also part what makes you happy? I wrote a couple of books, including Things a Computer Scientist Rarely Talks About, that are about theology — things you can’t prove — rather than mathematics or computer science. My life would not be complete if it was all about cut and dried things. The mystical things I don’t understand give me humility. There are things beyond my understanding.

In mathematics, I know when a theorem is correct. I like that. But I wouldn’t have much of a life if everything were doable. This knowledge doesn’t tear me apart. Rather, it ensures I don’t get stuck in a rut.