Last night Lauren Conrad went on Letterman to promote The Hills. And it wasn't boring! "Was it Heidi you're having the problems with?" Dave asks. "Yeah," Lauren replies. "It's been years, so throughout the show we've had problems with everyone." And then Dave says what we never realized we always knew: "Maybe you're the problem." Yes! He then tries to explain his logic to her, saying how for a long time he thought everyone was an idiot and then it occurred to him maybe he's the idiot, which turned out to be true. "Does that make me an idiot, then?" Conrad says. We'll let you all answer that in your heads.