Teaching axe teaches people how to teach axe (lesson): Lu Ban, a native of Lu in the Spring and Autumn Period, was a famous carpenter. Dancing in front of Luban with an axe. Showing off your skills in front of experts is a metaphor. {Example} I really overreached myself in front of all the old masters' interview experience. Different meanings in ancient times: In ancient times, people were criticized for being ignorant but good at showing off, but now they are encouraged to show off boldly, dare to show their skills, challenge authority, and sometimes say "an axe must teach".

remove doubts and misgivings

The idiom "teach others how to teach others how to swim" means playing with your knowledge in front of experts. There is also a saying with similar meaning, which is called "selling hundreds of surnames before saints". In front of Confucius, it is also ignorant to show off that you can recite "Hundred Family Names".