Any fool can write code that a computer can understand. Good programmers write code that humans can understand.

When you actually sit down to write some code, you learn things that you didn't get from thinking about them in modeling terms...there is a feedback process there that you can only really get at from executing some things and seeing what works

I've learned to always avoid saying "always"

I can't choose whether someone is offended by my actions. I can choose whether I care.

Why is composing symphonies tough? I don't know. It's just very few people in the world can do it well. And I think that's the case with upfront design. It is very hard to do well.

When to use iterative development? You should use iterative development only on projects that you want to succeed.

One of the things I've been trying to do is look for simpler or rules underpinning good or bad design. I think one of the most valuable rules is avoid duplication. "Once and only once" is the Extreme Programming phrase.