As if we needed another reminder,
So who was it? A world leader? A beloved children's book author? A fellow talk show host or political pundit?
None of the above. It was Sarah Koenig, host of the enormously popular podcast sensation "Serial."
And the secret of winning Colbert's undying affection, aside from creating an absorbing bit of documentary reportage, was simple flattery.
"What does it mean to have the most popular podcast in history?" Colbert asked. "Serial" has had 5 million downloads since it debuted in October. "What is the benefit of doing this?" he continued.
"Well, I'm here," Koenig responded.
That was all Colbert needed to hear.
"You're my favorite guest of all time right now," he said.
The first season of Koenig's epic project, which has investigated the 15-year-old murder case of Hae Min Lee in real time over the course of 12 episodes, will conclude with the final episode on Dec. 18. (Coincidentally, it's the same day as Colbert's final Comedy Central show.)
While no one should expect satisfactory conclusion to the case — this is real life and not a crime novel — the podcast has succeeded in rekindling interest in the fate of Adnan Syed, who is serving a life sentence for the murder. The podcast has raised questions as to whether he is actually guilty of the murder.
In January, the Maryland Court of Special Appeals will decide whether Syed will be able to appeal his case.
But by then, Koenig will have moved on to something else. The second season of "Serial" will tackle an entirely different story, though she hasn't said what it will be.
As for this case, Colbert was keen to keep her as grounded as possible.
"As a journalist, did you always want to do true crime reporting that people listen to on a treadmill?" he asked.
You can watch the full interview here.