Speaking to the Radio Times, the X Factor judge confessed that he was upset by the 'Angels' singer's reluctance to confront him personally before they famously made up and Williams re-joined Take That.
"All those years I'd just imagined this moment to actually be sat there opposite this person who had done so much damage and said so much bad stuff. Not to my face, in records and in print. It was the way it was being done that hurt," Barlow explained.
However, Barlow spoke positively about the pair's reconciliation: "To eventually be sat there opposite [Robbie] was liberating.
"And you know what, a lot of people don't get that chance, they spend their whole lives as enemies and don't talk.
"So for me it was a victorious day. And we came back to it a couple of days later and did some more and we were washed and we were clean."
Meanwhile, speaking about Williams's future with Take That, Barlow added: "Many fans say they prefer Take That as a foursome. The ultimate dream was to get us on tour. We managed to do that. It was beautiful.
"Now Rob's doing a solo record and from this point it's back to where it was. [But] you know what, we can revisit it whenever we want.
"He's our brother, Rob is, and if he wants to have a year off being Robbie Williams, he's welcome any time he wants."
In response to Barlow's comments, a band representative yesterday insisted that Williams is only "on a break" and will return to the boyband after he finishes work on his solo album.
> Video: X Factor Gary Barlow, Robbie Williams clash over Craig Colton
Watch the video of Robbie Williams and Gary Barlow single 'Shame' below: