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David Letterman returned to 'The Late Show' this week for the first time in seven years.

The 76-year-old talk show legend stepped down from his long running role in 2015 after 22 years with Stephen Colbert taking his place at the iconic desk, and the pair finally came together for a special interview on Monday night.

Asked what he misses most about hosting the show, he admitted: "I miss everything."

He added: "Mostly it's fun. 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.

"And that's a pretty good device. Then when you do something you're really proud of, you think 'My god, let's do that again!'

"And six or seven years later you have that experience once more."

Towards the end of the interview, Letterman asked Colbert if he could take a photo behind the desk, and he immediately got to his feet to let him take his seat for old time's sake.

He said: "This is very generous of you. Thank you, Stephen."

He later quipped: "By the way, in my day, I never would've let this happen. I'm sorry. Thank you."

The pair - who recreated a selfie Colbert took in 2014 when he was a guest on the 'Late Show' - also laughed about the current host's "supplies" behind his desk.

He said: "I've got a question for you. Again, very few people know what it's like to host. What do you think about my supplies [behind the desk]? Anything like what you had?"

Letterman joked: "What, all this weed?"

The TV icon previously revealed he felt fine about his decision to step down from the show until his final day.

He explained: "Everything felt fine until the last show. I felt great about the show until all of the set was in a dumpster out on 53rd street. And then it was suddenly 'ohh yeah, that's show business.' "