You know what it's like when you're driving along on a tarmac motorway, and it switches to concrete/cement? The noise gets suddenly loud, the drive gets hard, and the car vibrates as it "drums"? It's like that. But you're on tarmac and doing 63mph!
You have to turn the radio up, talk louder, and if you drive like that for a while, your fingers/grip starts to go tingly & numb. You certainly can't grip the wheel for long in the manner in which your driving instructor would tell you!
If you have it, you'd know.