It’s times like this that make you realize just why the internet was created. Case in point. David Tennant and Stephen Colbert crossing paths recently on CBS’ The Late Show and it was greatness. The brief but brilliant interchange occurred before the show had even begun.

As things played out, Colbert dropped into the show’s green room before the show to meet his guest, telling Tennant that he’d been his favorite Who. Fortunately, this only served to put the ball on a tee and create confusion for Tennant about just ‘what’ or ‘who’ Colbert was actually talking about and…the rest is video gold.

What started out as a simple Colbert admission, “When it comes to Doctor Whos, you were my favorite”, quickly escalated into a classic Abbott and Costello “Who’s on First” sketch as Tennant asks, “Favorite what?” With Colbert specifying, “Favorite Who.” Tennant pushes for further explanation, asking, “Favorite who what?”

Some may remember an earlier exchange from several years ago with another Late Night host, David Letterman. Trying to understand just how U.S. audiences would know David Tennant, Letterman seemed quite intrigued as to how the rest of the world got acquainted with the Scottish actor, asking Tennant, “For God’s sake, what do people know you from? Do they say ‘You’re the guy from Gracepoint.’ Or Church Town? or Doctor Who?” At this point, Tennant schooled Letterman as to the world of Doctor Who 101 (approximately 4:30 in)

Historically, Colbert has always been a good friend to our favorite British stars and, somehow, creates video gold each time out. You may remember he and Tom Hiddleston’s impromptu singing of “See the Light” or when he coaxed the cast of Downton Abbey to read the script with an American accent. Forget the endless cat videos, THIS is what the internet was invented for.