I'm looking for quotes from known game industry professionals (designers, developers, etc.), relevant to the topic of game development.
Please one quote per answer and cite your quotes with a link to a primary source, if possible. (and a link to the person's bio wouldn't hurt).
Hopefully this will become a collection of great quotes that can be referenced (e.g. in presentations) or, in my case, possibly to write on the board at my game dev club meetings to prompt discussion.
Also please no duplicates from the Stack Overflow question "Great programming quotes".