pax is absolutely spot on.
In fact, I feel I really have to amend the first sentence of my post above to read: I tend to agree that this sort of excellent performance is not solely a matter of going over scenarios in one's head.
"It is long been a principle of ours that one is no more armed because he has possession of a firearm than he is a musician because he owns a piano. There is no point in having a gun if you are not capable of using it skillfully." -- Jeff Cooper