Apparently Mark Roswell, or "Dashan", is the most famous Canadian in China, famous for his incredible facility with Mandarin. He not only speaks it fluently to the point that native speakers can mistake him for Chinese, but he also speaks it comedically, even excelling in a comedy form called "crosstalk."
He was just a normal guy from Ontario, curious about a language.
In this documentary, you see his underlying love of the country and the language. Surely this love is crucial to stay on the road toward such fluency.