My first program taught me a lot about the errors that I was going to be making in the future, and also about how to find errors. That's sort of the story of my life, making errors and trying to recover from them. I try to get things correct. I probably obsess about not making too many mistakes.

Science is knowledge which we understand so well that we can teach it to a computer; and if we don't fully understand something, it is an art to deal with it.

I can’t go to a restaurant and order food because I keep looking at the fonts on the menu.

Beware of bugs in the above code; I have only proved it correct, not tried it.

Science is what we understand well enough to explain to a computer. Art is everything else we do.

God is a challenge because there is no proof of his existence and therefore the search must continue.

... the designer of a new system must not only be the implementor and the first large-scale user; the designer should also write the first user manual. ... If I had not participated fully in all these activities, literally hundreds of improvements would never have been made, because I would never have thought of them or perceived why they were important.