The patient grandfather

A woman in a supermarket is following a grandfather and his badly behaved 3 year-old grandson.
He has his hands full with the child screaming for candy, cookies, and pop.
But the grandfather works his way round, saying in a controlled voice, "Easy, William, we won't be long now ... easy, boy."
Another outburst and she hears him calmly say, "It's okay, William, just a couple more minutes and we'll be out of here. Hang in there, son."
At the checkout, the little terror is throwing items out of the cart, and Granddad says, again in a controlled voice, "William, William, relax buddy, don't get upset. We'll be home in five minutes. Stay cool, William."
Very impressed, the woman goes outside where the grandfather is loading his groceries and the boy into the car.
She says, "It's none of my business, sir, but you were amazing in there. I don't know how you did it.
That whole time, you kept your composure, and you just calmly told him things would be okay. William is very lucky to have you as his grandpa."
"Thanks," says the grandfather, "but I'm William ... the little ba*tard's name is Kevin."