For me, it's more like "Begin with a mission, not a goal."
I originally talked to Ben about this, and it sort of hearkens back to the whole debate on visionary vs. tactical leaders.
Paul Graham said recently, "If you have some kind of big visionary plan, you're probably Webvan." That's absolutely true. Starting with a niche feature (Payments for Palm Pilots, not payments for everyone--PayPal. Profiles for college students, not generic social networking--Facebook) and making it work insanely well is crucial. But, that's all about executing on a certain goal.
PayPal and Facebook also dared to aspire to something much greater from the beginning. As the post mentions, to become truly successful, there has to be a greater "there" there. If you don't have a mission, you'll execute on your goals at half-effort at best.
