The light-heavyweight, 28, made his comeback on Saturday after two years of frustration which almost led to him giving up the sport.
He signed with Frank Warren after the Delhi Games in 2010 but became disillusioned, having only fought six times in four years.
"I wasn't in the ring as much as I was told I would be but I wouldn't say it's all Frank's fault," he said. "In the last year or two, I drifted out the sport as I was frustrated, but that's all gone now. Sometimes things don't work out the way you hope."
His second-round stoppage of Egidijus Kakstys in his home county of Lincolnshire on Saturday was on a show put on by the Englishman Carl Greaves, who wants to have more fights in the area with Johnson as the big attraction, but the boxer himself wants to come to Scotland as often as possible and is hopeful of a place on the undercard for Ricky Burns' next fight on June 27.
"It was as if a year of frustration just exploded out," said Johnson. "I'd been training well and I was in a good frame of mind so I wanted to do a job. It was only my second fight in two years so it's good to get rid of the nerves and get the whole experience again. I want to do as much as possible to make up for lost time."
Johnson was barely out of the ring before he linked up with Carl Froch to spar on Tuesday ahead of the super-middleweight's rematch with George Groves on May 31. "He's the unified champion of the world so it doesn't get much better," said Johnson.
Trainer Joe Gallagher has taken over as his manager and Johnson said: "I want to keep coming to Scotland. My heart lies with Scottish boxing; all my amateur teammates are there and I have a good fanbase.
"I wouldn't say I'm Scottish; I'd say I'm British. My dad was born in England and that's where I grew up but my mum's side are from Glasgow. When I was boxing for Scotland, I did feel Scottish and I was so proud to be representing Scotland."
He had a message for Scotland's Glasgow 2014 hopefuls, too: "Enjoy it because it comes and goes so quick."