Forcas on yer skool
Lit. Read your books. In context of where the meme originated, the full sentence should be "Focus on your school and stay out of this."
A meme originated from a Chinese children's show Little Fairy Balala. The show itself is like a mix of Precure and common magical girl story, and its very first incarnation in 2008 was played by real life actors. While the series is continuing in animation form, this particular meme is closely associated with the oldest 2008 version, and only went viral very recently.
In the show, there is a character called Prince Youle (游乐, lit. having fun). He is a masked man that fights alongside the two protagonists, and a bit cynical in nature. The actor that portrays him speaks both Cantonese and Chaozhou-nese, and has a thick accent that somehow mixes traits from both dialects, which seriously undermines his line delivery in Mandarin, and made many of his lines sound extremely funny. The most famous, as well as the first, misheard line from him is "none of your business." While there are quite a few more out there, this one is basically ground zero that started the whole meme trend.
Some other popular picks include Don tell me whatwodu, Wai you lai dis, and Chuuden shuu aakt laik chuuden.
