Steve Jobs perfect response to an insult. Worldwide developer conference 1997.
I like that he noted you have to start with the user experience first and then work backwards from there. Love or hate him, he was a very smart businessman in the sense that he really knew his customer. If you invent a world changing piece of technology, but nobody knows how to use it, that technology is useless. You need to make sure the people you market your product to can actually use it, or else will never take off.