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.
I wonder how many things we're all going around doing badly because the idea of not knowing how to do them well seems too ridiculous to admit to.
...You've probably never been taught to have a conversation. I've had exactly one class on it and it was in the last six months. I know damn well that many people have not self-taught this well... In general there's this entire class of implicit skills that we mostly don't think of as skills, that we're entirely self-taught on, and that we practice sufficiently non-demonstratively that we can't easily watch what other people do. The result is a very personal skill idiolect.