The general principle is: cached is fast, cache-populating is slow. This goes for mind and "body" both, because the body does as its told, but it needs telling in a lot of detail and the control signals need to be discovered. Most people, for both mind and body, learn enough control signals for day-to-day use, and stop.
I do somewhat wonder what it would be like to know the control signals for all my muscles, Bene Gesserit style.
Vladimir Vasiliev is a Bene Gesserit, at least for skeletal muscle. Unfortunately, I can't locate any of the videos that really demonstrate this on youtube; but it makes him able to do some strange-looking things very effectively.
Here's the new thread for posting quotes, with the usual rules: