NEW YORK (September 22, 2009)--By the time Barack Obama came on stage for the taping of the "Late Show" on Monday, host David Letterman had offered up 10 reasons why in the world the president had agreed to do it.

Among Letterman's theories: Mr. Obama said yes without thinking about it, or as Letterman put it, "Like Bush did with Iraq."

But Mr. Obama had other ideas.

It turns out he was listening when Letterman had bantered with a woman in the audience who brought a potato in the shape of a heart to the show.

Mr. Obama told Letterman: "The main reason I'm here? I want to see that heart-shaped potato."

The woman tossed the potato to Letterman.

She agreed to let Mr. Obama keep it.

"This is remarkable,” the president said.