What you get on paper is so shallow that you never know what you have to do.
Meaning: The knowledge gained from books is simple after all. Finally, if you want to know the essence of things or things, you must practice it yourself.
What you get on paper is superficial, but you never know that you have to do it-read Lu You's Winter Night and Show the Children. This is a godson poem by Lu You, and its name is Reading on a Winter Night for Children.