"When I lost the Democratic primary for re-election in 2006 in Connecticut, it was the most painful moment - most disappointing moment - of my political career," Lieberman said in an interview set to air on CNN's John King, USA. "Yet as I look back to it, and it sure didn't feel like that then, I feel like I was done a favor."
After losing the Democratic primary to Ned Lamont, Lieberman ran in the general election as an independent, besting Lamont and the Republican challenger in order to hold onto his Senate seat.
Lieberman told CNN Chief National Correspondent John King that being an independent has worked to his benefit.
Not being in either party, "I think put me in exactly the position I want to be in at this hyper-partisan, non-productive, divisive time in our politics. And it gives me the latitude to try to be a bridge on a lot of different issues, to make things happen. Or sometimes not to be a bridge. Just to speak out and say what I believe - whether it makes everybody on one party or another happy or not."
The normally outspoken Lieberman also refused to weigh in on Florida Republican Gov. Charlie Crist. Once the favorite, Crist is now trailing in the polls in Florida's GOP Senate primary and has until the end of this week to decide if he will abandon the GOP and run as an independent.
"[E]very campaign - every individual - is a different situation," Lieberman said of Crist.
And asked about his plans for his next re-election bid in 2012, Lieberman said that "probably most likely" he'd run again as an independent.
"But I wouldn't rule anything out - and that is running on either of the other parties," the Connecticut lawmaker said.
Lieberman also discussed his role in the comprehensive energy bill intended to deal with climate change, the recent attention being paid to immigration reform during this election year, the overall political climate in the country and the growing dissatisfaction with government.
Watch Lieberman's sit-down Monday on CNN's John King, USA beginning at 7 p.m. ET.