Van Persie is preparing for his first Manchester derby on Sunday after deciding to bring an end to an eight-year stint with Premier League rivals Arsenal.
The Dutchman had the chance to sign for City but insists he is happy with his decision to head to Old Trafford.
"I made my mind up very quickly and I am coming into work with a big smile on my face every day," Van Persie told MUTV.
"It is not really work, it is my hobby - I love football. But everyone has been so nice to me and I have been having the time of my life here.
"So I don't regret that - but of course in a derby you have lots of people involved - the fans and the players.
"Everyone is really committed and wants their team to win and we'll do all we can to win too."
Van Persie is eager to help United claim victory at the Etihad Stadium and extend their advantage at the top of the table to six points.
He added: "Anything can happen but that's the case with us every week. We want to stretch our lead and keep our run going."
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