The 28-year-old joined his former Swansea boss Brendan Rodgers at the Celts in the summer after disappointing spells at City and Villa.
He has been in fine form this season and has managed to score 25 goals in all competitions.
When he asked if he is fancying a summer move to a bigger club, he said: "Not at all. I've found my happiness and I'm enjoying every minute at Celtic and I wouldn't think of a reason to leave.
"I wanted the enjoyment back so why would I want to leave and find myself back in a situation I was in last year or the year before?
"I'm in no rush to leave here. I've had all these moves before.
"I moved to City and it didn't work out, I went to Villa and got relegated, and now I'm enjoying playing every week, scoring goals, back to my best. Why would I want to ruin that?"