Bruce could have taken over at St James' Park when he was at Birmingham City, but says he didn't move because he was worried about his reputation as someone who moved clubs too easily.
"I could have done, and in hindsight it was a mistake I didn't go there," Bruce told Sky Sports.
"It was just the timing of it, I'd committed myself to Birmingham at the time and there was this stigma about loyalty with me at the time. I only had four clubs as a player, I seemed to have four clubs in 20 months when I was a manager!
"I always think what if. But as I said I'd committed myself to Birmingham at the time and it didn't happen so I had to see it through and there you go."
Bruce admits he still dreams of managing England or a club in the Champions League.
"It took me a long time to get to Sunderland which is a very very big club in terms of stature, a big support, huge expectation. You've got to be driven by something," he added.
"We all want to rise to the top and manage in the Champions League or manage your country or whatever you want to do, so I'm never going to give up on it.
"I doubt it will happen because I do think you get pigeon-holed. You get pigeon-holed with which way you manage, but I'm not going to give up hope that one day maybe it will happen."