The Bayern Munich forward reveled in his club's latest triumph, seeing the 2-0 win over Raja Casablanca as the perfect finish to a remarkable 2013.
Goals from Dante and Thiago Alcantara earned the Bavarians victory and added a fifth trophy to their Champions League, Bundesliga, DFB-Pokal and UEFA Super Cup successes earlier this year.
Muller, speaking after the game, revealed his great satisfaction with yet another title to die Roten's already impressive haul and believes that his side can now go into the winter break without any regrets.
"Our opponents did what they could to make it a tough match," the 24-year-old told the club's official website. "We would have liked to score another goal or two, but Casablanca didn't make it easy, even in the second half. We won 2-0 and that's what counts.
"We’re happy to be Club World Cup champions. It’s a fairytale ending, the well-earned reward for the excellent year we’ve had. It's nearly impossible to play at the level we’ve done in this calendar year. After this win, we can go into a relaxing holiday with a clear conscience."
Bayern is also well set to enjoy a successful 2014, seven points clear of nearest rival Bayer Leverkusen in the Bundesliga with a game in hand and preparing to face Arsenal in the Champions League last 16.
With those challenges ahead, coach Pep Guardiola urged continued focus from his players in 2014.
"Five trophies in one year is an incredible success for Bayern," the former Barcelona boss said. "I'm very happy for the club and very proud of my players and the fans. We have a two-week break ahead of us and we'll come back to tackle the challenges that lie ahead. We’re very happy with our achievements, but we have to look forward."