The ill-fated stint at Meadow Lane, with Campbell walking away after that one appearance, is just a bad memory.
"To me, it's the past," he said. "Yeah, it's been a strange old season, but I'm knuckling down now."
After Sunday's Manchester United game, Arsenal face successive fixtures against Chelsea and Liverpool. When asked if lifting the Premier League trophy for a third time with the North London club was feasible, Campbell laughed. "There's a long way to go," he told The Times. "The main thing is to keep focused.
"United will drop points, Chelsea will drop points, everyone will. It's going to come down to who gets the run going, the wins, the draws, who keeps ticking along. They're all there, all the top sides. Anyone can win it. You've got to dig in, fight, believe in yourselves. That's what it's all about."