https://ling-lingchinese.com/2016/07/09/a-chinese-joke-%e4%b8%ad%e5%9b%bd%e7%ac%91%e8%af%9d%ef%bc%9a%e5%ad%a6%e9%97%ae%e6%97%a0%e7%94%a8-knowledge-is-useless/