Everyone makes soju and doesn’t show off that he is a master. What does it mean? Isn’t that a leak? How to explain this sentence? I heard it said by Lao Liang

"Everyone who makes soju must not reveal that he is a master" and "Everyone who sells soju must not reveal that he is a master" have similar meanings. Among them, "Jiajia" means everyone, and everyone can make soju, while "bulu" means being careful, not omitting, and keeping the quality of the wine intact. It can be understood as having superb skills in the soju-making industry and being able to do it. People who are good at their jobs. This sentence can be understood to mean that everyone can make soju, but only those with professional skills and careful work can truly make soju.