Sir Paul McCartney had the perfect response after losing to his grandkids at "Beatles Rock Band," the video game that allows you to strum along to your favorite rock and roll hits.

On The Tonight Show Starring Jimmy Fallon the other night, McCartney expressed good-natured frustration with the game.

"Are you kidding," he told Fallon, "it's very hard!"

He said every time he plays against his grandkids, they kill him. But McCartney isn't phased.

"I just tell them," he quips, "I wrote [that song!]"

You can watch the entire clip here: