The primary thing when you take a sword in your hands is your intention to cut the enemy, whatever the means. Whenever you parry, hit, spring, strike or touch the enemy’s cutting sword, you must cut the enemy in the same movement. It is essential to attain this. If you think only of hitting, springing, striking or touching the enemy, you will not be able actually to cut him.
The McNamara fallacy, named for Robert McNamara, the US Secretary of Defense from 1961 to 1968, involves making a decision based solely on quantitative observations (or metrics) and ignoring all others. The reason given is often that these other observations cannot be proven.
The fallacy refers to McNamara's belief as to what led the United States to defeat in the Vietnam War—specifically, his quantification of success in the war (e.g., in terms of enemy body count), ignoring other variables.
What’s important to you in the development of a product?
One of the things that really hurt Apple was that after I left John Sculley got a very serious disease. And that disease — I’ve seen other people get it too — it’s the disease of thinking that a really great idea is 90% of the work, and if you just tell all these other people “here’s this great idea,” then of course they can just go off and make it happen.
The problem with that is that there’s just a tremendous amount of craftsmanship in between a great idea and a great product. And as you evolve that great idea it changes and grows. It never comes out like it starts, because you learn a lot more as you get into the subtleties of it, and you also find there are tremendous tradeoffs you have to make, there are just certain things you can’t make electrons do, there are certain things you can’t make plastic, or glass, or factories, or robots do. And as you get into all these things, you find that designing a product is keeping 5,000 things in your brain, these concepts, and just fitting them all together and continuing to push to fit them together in new and different ways to get what you want. And every day you discover a new problem or a new opportunity to do it a little differently. And it’s that process that is the magic.