The Marseille midfielder has spoken of his sadness about the controversial dismissal, how it affected his passion for the game and how that spirit has been renewed in France
The Liverpool-born midfielder, who is now on loan at Marseille, was given a straight red after lashing out at Carlos Tevez and two other players, which led to QPR, 2-1 up at the time, going on to lose 3-2.
A 12-match ban prompted a move to France and, following his first four appearances for OM, he spoke of his disillusionment with football in the Premier League.
"I became a bit p****d off at football, if I'm being honest. I was in two minds," Barton told Sports Illustrated.
"I was really upset with the way I behaved, and I was thinking, do I really need to put myself through this anymore?
"I'm in a good financial position after a 10-year career in the English Premier League. My passion for the game had sort of dissipated."
Barton has outlined his desire to stay at Marseille in the past week, expressing an affinity for the city and its attitude towards football and life, comparing it to his hometown.
"It's very similar to the place I grew up in. Marseille and Liverpool are both major ports, and there are similarities in terms of the economic and social situations. I really get it. Even though I don't speak the language, it felt right," he continued.
"Football and life, there's no difference between the two in Marseille and Liverpool. In Paris and London, life and football are two separate things."