Read The Witty Rejection Letter David Letterman Sent Jimmy Kimmel In 2002

Jimmy Kimmel, 46, has idolized David Letterman, 66, since the younger late-night show host was a quirky kid growing up in Las Vegas.

Kimmel has often joked the only reason he went into show business was to be friends with Letterman and wondered why anyone would watch his show instead of Letterman's.

So, when Kimmel was coming off four years as co-host of Comedy Central's "The Man Show" and about to debut "Jimmy Kimmel Live!" on ABC in 2002, naturally he reached out to Letterman to be a guest on the show's premiere episode.

Letterman's typed response - on personal stationary, nonetheless - is now framed on Kimmel's desk in his studio office, alongside a photo of his late grandparents and a picture of himself covered in whip cream after popping a fictional zit on Jon Stewart's forehead.

Read the letter, uncovered by New York Magazine during a 2012 interview with Kimmel, below:

September 23, 2002

Dear Jimmy,

Thanks for asking me to appear on your premiere. Unfortunately, I will be out of the country on business. I'm sure the program will be a success regardless.

Sincerely,

Dave.

"His response is hilarious," exclaimed Kimmel to New York Magazine. "He's not out of the country on business. He knows you know he's not out of the country on business and just the words 'on business' - it really makes it a perfect letter for me."

Ten years later, the two aren't exactly best buddies but Letterman did appear on "Jimmy Kimmel Live!" for the first time in 2012 as the LA-based show broadcast out of Brooklyn in the wake of Hurricane Sandy.

Letterman's appearance gave Kimmel his biggest Wednesday audience in the show's history - about 2.4 million viewers.

Leading up to the visit, Kimmel said he was "terrified" to interview Letterman and tried to justify it by saying, "I'm sure for him it's nothing more than a nuisance, that he's just doing it to be nice."

But Letterman was a gracious guest Wednesday as Kimmel showed him photos of his "Late Night"-themed 18th birthday cake and "L8 Nite" license plate on his first car.

Letterman responded by telling his number one fan, "I'll be honest with you, it was troubling. I kept saying to people, 'Why is he sucking up to me?'... When I was persuaded that there was some measure of stability here, then I really realized that it was genuine and I couldn't appreciate it more."

Letterman added, "In show business, one of the precepts is you're not really supposed to be nice to people, especially if you have the same occupation as another person. Jimmy has broken that precept and has been nothing but generous and courteous and kind to me."

Watch Letterman's ratings-raising appearance on "Jimmy Kimmel Live!"