As you become "good" at driving in harder conditions, you'll use your butt (which is really how you're physically connected to the vehicle) to figure out the traction state of the car, to know if the car is sliding, if it's close to losing the rear end or the front end, if it's pitching down or up, and so on. This is how you know which corrections to make to the vehicle to keep it going fast without losing control.
Pilots of small planes do the same thing. After a while you can just feel small accelerations and change of directions without needing to check some of the instruments.