Watch a dog after a fright. It startles, holds still a moment, then gives one full shake from nose to tail and goes back to sniffing the hedge. The whole event is over in seconds and nothing is carried into the afternoon.
People have the same equipment and considerably more commentary. The stress does leave — after a hard phone call your hands are steady again within minutes. What lingers is the thinking about it, which is a separate thing, and can be set down separately.