Mills sashayed across the Dancing With The Stars dancefloor, he felt revitalised and renewed.
It wasn't the 39-year-old's heart pounding after an upbeat routine, or the culmination of weeks of gruelling training with his partner Alarna Donovan on his body.
It was the joy that he felt on stage reminding him of something he loved to do – perform – that made him feel brand new.
"The show was just the medicine I needed," Rob, 39, tells TV WEEK.
"After being inside for so long you can forget how much you love it. Then when you're actually performing, it's like 'oh, I love that. I love performing, I love dancing.' I wasn't singing, but it's still pretty good."
But dancing wasn't the only highlight for the Australian Idol alum, it was the experience of being surrounded by live music, performances and most importantly, people.
"We had a small audience during filming but we were the audience too," he says.
"We were sitting on couches watching, supporting, hooting and hollering everyone out there dancing. I loved it, it felt like going to a gig every night except it was watching your friends. It felt great to be a part of something again."
Rob's first appearance on DWTS was in 2009. Juggling his routines with a full-time role in Wicked the musical, he was eliminated only two weeks into the competition.
"I was pretty shattered getting kicked off second, but I was just so flat out. I got kicked off the show but I was still dancing every night which was awesome," he says.
This time around, Rob is older, wiser and has a hell of a lot more experience moving and shaking on stage. So much so that he is back with a vengeance, and a lot to prove.
But aside from working hard to win money for his charity, The Australian Children's Music Foundation, Rob wants Australia to know how beneficial having a boogie really is.
"We're up there dancing sober and it made me realise that a lot of people around the country drink so much before they go into a nightclub to dance," he says.
"But dancing is great for your body, your soul, it makes you feel good. Awkward and weird, too, but it's just a really good way to express yourself."
While the former Neighbours star has definitely found his groove, when asked if he would whip out a ballroom routine with his fiancé, journalist and The Project presenter, Georgie Tunny, at their upcoming wedding, he couldn't stifle a laugh.
"I don't think you know Georgie Tunny," he giggles. "Look, she loves the dance floor, she loves a boogie, but she's not a great dancer. She is enthusiastic but we'd need a good couple of years of training."
After his appearance on DWTS, and then, a spot of co-hosting The Morning Show with his fellow dancing star Kylie Gillies, rumours have begun to circulate about whether Millsy is a front runner for hosting the upcoming Australian Idol reboot later this year.
"I haven't heard any whispers but I would just love to be a part of the show," he shares.
"Whether I'm judging or hosting, I think I'd love it. I just love mentoring. I mean, I teach kids and I love giving feedback and helping them to become better humans and better performers. So if I had that opportunity, I'd jump at it. I really would."
DANCING WITH THE STARS: ALL STARS, Sunday, 7pm, Channel Seven.