The unconscious mind is what we want running the show when we are shooting. All of the almost miraculous reflex actions we have performed in our lives were guided by the unconscious which I have read various numbers for but that includes a thousand times more powerful than the conscious mind that is verbally talking to you. I don't think there is a real number known but it is worth remembering the unconscious is far more powerful than the conscious. No reason to have the conscious in the way. I have learned it is idling in a corner somewhere and will step in if it needs to like when you miss shape a little.
Precision comes from the same place that the "impossibly fast" reactions come from. The verbal conscious mind can get between the unconscious and the body and make a mess of things. My brother was driving my truck when we came to a fork in the road from the other direction. A driver didn't realize they didn't have the right of way forking left. Closing speed of well over a hundred miles an hour, my brother split the gap with no visible daylight between any of the three vehicles, not a scratch on my truck!
Of course you have to have the space to do this but it is also the unconscious at work. Not the conscious, or the subconscious, they are three different things. Once I could define them clearly but it has been a long time since I studied such things and I settle for general concepts these days.
Those who have already said we can train the conscious to shut up are absolutely right, required work for me and I suspect most of us. One thing that helps is a key. In pool the obvious key is bending over. The old adage, think standing, act only once bending over, is true.
Something that took me even longer was to think standing before my first shot of an inning then only stop and think again if something went wrong. Otherwise the entire inning should be one continuous motion, mentally if not physically. Got to be careful though, I had two people quit me midset within a week or two of each other when I started what I had named stalking the table many years before. I wasn't graceful enough to call it gliding around the table!(grin)
Hu