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.

The best programs are written so that computing machines can perform them quickly and so that human beings can understand them clearly. A programmer is ideally an essayist who works with traditional aesthetic and literary forms as well as mathematical concepts, to communicate the way that an algorithm works and to convince a reader that the results will be correct.

Computers are good at following instructions, but not at reading your mind.

Always remember, however, that there’s usually a simpler and better way to do something than the first way that pops into your head.

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

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

... 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.