It's best to talk about a clever boy like jk, a silly boy and nk in Andy Lau's silly children's songs.

I thought jacky he said was Jackie Chan! Because Jackie Chan's name is Jack, isn't it?

Actually Jacky is Wu Zongxian's English name ~ANDY is Andy's English name ~

There is a version of this song sung by Hua Zai, Wu Zongxian and Ke Shouliang ~

So this word is just a joke on themselves ~