If you grew up in the '80s or '90s, David Letterman - at the height of his powers and fame - was exhilarating to watch.

He winked right down the lens at the camera and was completely aware of how ridiculous his guests were, how the cult of celebrity wasn't worthy of much respect, and how the very contrived nature of interviewing someone for ten minutes wasn't something to be adhered to. This was a man who cut off Mel Gibson's pants mid-interview because it was too warm on set, and had Peter O'Toole arrive out on the back of a camel. He threw things off high buildings and tried to have hot-dogs brought to the set by shouting down on street with a megaphone. In short, David Letterman paved the way for the prank-filled, celebrity-clashing comedy segments that Kimmel, Fallon, Colbert and Conan have worked with since then.

Therefore, to see him so forcefully remove himself from all this and to strike out in a totally different direction is not only interesting, but utterly jarring. Though each episode is an hour long, you find yourself waiting for about twenty minutes for Letterman to drop the serious schtick and break out the Late Night Action-Cam or ask Barack Obama to do some Stupid Human Tricks. Instead, what we see is a sedate, thoughtful Letterman ask well-researched questions and allow his guest - the first one being Barack Obama - to answer them with as much or as little detail they please.

While the format isn't something that's terribly unique - podcasts such as WTF with Marc Maron have been basically doing this for years - it is fascinating to see Letterman adapt to this style; not even adapt, but fully embrace it. He even mentions it himself during one question, where he quips that he's smarter than people think. It's a fair point, but then again, Letterman spent decades building up this image as a self-deprecating, knowing comic interviewer - so why the change now? It's hard to say, really, but one thing is for certain - Letterman is not only enjoying the experience, he's exceptionally good at it.

Though he can skilfully inject an odd witticism or joke here and there, Letterman keeps the tone earnest and sincere in a way throughout that can come across somewhat as being a little too safe. Again, for a person who spent so much of his career brooking hard against structure and revelling in chaos, to see him be so staid and composed is shocking in and of itself. The first episode uses archival footage and brings in an interview with civil rights hero John Lewis, where he discusses the Bloody Sunday event in Alabama, and how his work inspired Barack Obama into action as a young man.

It's a fascinating insight into a political figure, and Letterman does it skilfully and assuredly in a way that, by the end of the first episode, will have you wondering why he hasn't done it sooner. While the serious, but relaxed, nature of this episode may be jarring, there's hope that future guests may see Letterman return to his comedic roots - as further guests include Tina Fey, Howard Stern, George Clooney and Jay Z.


My Next Guest Needs No Introduction is now on Netflix UK and Ireland.