David Letterman returns to 'The Late Show' and reveals what he misses most and what he thinks of Colbert's version of the show

David Letterman made his triumphant return to The Late Show on Monday, eight years after handing over the keys to Stephen Colbert. And the former host had “a few observations” about the new operation while looking back on some of the things he loved and misses most.

Other than wishing his wife a happy birthday, Letterman had no real agenda for being on the show other than to catch up with Colbert and drop a few classic Letterman-isms and jokes along the way.

Here’s a look at the conversation between the host of The Late Show With David Letterman and the host of The Late Show With Stephen Colbert.

The improvements to the facilities… and the show

Among Letterman’s immediate observations upon arriving at the Ed Sullivan Theater for his interview was how good it all looked and how fancy it all was.

“It's like a mall, it’s unbelievable, it’s like Rodeo Drive,” Letterman said. “Ladies and gentlemen this is television of the future.”

Some of the things he was most impressed with included the snacks in the dressing room where there was also a menu provided.

“The dressing room is nicer than the nicest hotel I’ve ever stayed in my life. I’ll be here through Christmas,” Letterman joked.

However, it all boiled down to what was Letterman’s way of giving Colbert some due respect for the consistent work he’s done over these past eight years.

“Congratulations on the great success you and your staff have had,” Letterman told Colbert. “It must be very, very gratifying, and as a handful of people recognize, it’s not easy. But you make it look very easy. So congratulations again to you and the entire staff.”

What Dave misses most

After pointing out that he still has around 3,000 episodes of The Late Show to go to catch up with Letterman, Colbert asked the “Iron Man of late-night” what he misses most about the job.

“I miss everything. I mean mostly, it’s fun,” Letterman said “Very few things in life provide one the opportunity. And I can’t speak for you or to you on this topic, but for me, if you muck one up, 24 hours later you get to try again.”

He said knowing he had that freedom made it more and more fun and expanded on what that meant for the show.

“And then when you do something that you’re really proud of you think, 'By god let's do that again.’ And six, seven years later you have that experience once more.”

Letterman also took some time to talk about all of the great musicians and music that was involved with his show, both in-house and guest performances. And the latter seemed to be some of his favorite moments, most of the time anyway.

“Whenever Green Day would be on I was frightened by the drummer," Letterman said of Tré Cool. “Whenever they would finish, he would charge the desk and lunge at me, to the point where I assumed he was kidding around, or perhaps he wanted to hurt me. Looking back at that now I just think, 'Wow, what a great experience that was.’”

He also talked about his love of the band The National — who performed on Monday — and their willingness to leave their tour to come and play the show. He likened it to the time Foo Fighters did a similar thing to come and perform when Letterman came back from his heart surgery in January of 2000.

Recreating the selfie

After Colbert reminded Letterman that the pair took a selfie during Colbert’s appearance on The Late Show not long after he was announced as the next host in the spring of 2014, it was time to do it again.

“This is great because I was going to ask you if I could have my picture taken at the desk. Do you mind?” Letterman said.

After getting behind the desk he added, “By the way, in my day, I never would have let this happen, I’m sorry. Thank you. Do this because my son doesn’t believe I had a show.”

They did it. They shook hands and bro-hugged.

The rest of the host reunion

The pair also gave some love to mutual friend Dana Carvey, whose son died last week, while Letterman took some time to discuss what life is like now that he and his wife are empty nesters, and of course the “errands” that are involved in such a life that are either getting done, or being talked about getting done.

Letterman and Colbert also looked back on their final meeting together in Letterman’s office just a week or so before he officially left the building and Colbert moved in. Colbert recalled Letterman saying that one thing he wished he would have done was toy with moving the desk in a different spot on the stage, to the more traditional Johnny Carson set-up.

What Letterman remembered was Colbert asking if there was a place to go and hide from producers. Colbert picked up on the memory and said that the place Letterman mentioned is still in use and works great. And Colbert wouldn’t give up the location despite Letterman's pushing.

“You said, ‘It’s great because it’s close enough to where the producers are that you can hear them calling for you and they won’t know where you are. And they’ve never found me. But the secret might be, that they’re not looking. They may not care if I show up,” Colbert said.

The Late Show With Stephen Colbert airs on CBS.