David Letterman: 'I couldn't care less about late-night television'

David Letterman has truly moved on from his former career in late-night television.

In his first TV interview since retiring in May of last year, the former "Late Show" host said he doesn't look back at his old career at all.

"I thought for sure I would," Letterman told Tom Brokaw on NBC's "Dateline: On Assignment" when asked if he misses the late-night show. "And then, the first day of [Stephen Colbert's] show, when he went on the air, an energy left me and I felt like, 'You know, that's not my problem anymore.' And I've kind of felt that way ever since."

Letterman has been vocal about fully basking in his retirement - from time spent with his young son to rebelliously growing out a beard that's unpopular with his family and many of his fans.

"I devoted so much time [to career] to the damage of other aspects of my life," he told Brokaw. "The concentrated, fixated, focusing on that, it's good now to not have that. I couldn't care less about late-night television."

As for his replacement, Letterman said CBS didn't include him on those discussions. If they had, it sounds as if he would've advocated for a bold move for late night.

"I'm happy for the guys, men and women. There should be more women," he said. "And I don't know why they didn't give my show to a woman. That would have been fine. You know, I'm happy for their success. And they're doing things I couldn't do. So that's great."

The full interview will air on "Dateline: On Assignment" this Sunday at 7 p.m. on NBC.

Watch the excerpt from the interview below: