French saying of the day: “Don’t teach the old monkey to make a face” — What does it really mean?

French wisdom offers a colourful saying, "On n’apprend pas au vieux singe à faire la grimace," meaning you shouldn't try to teach someone what they already excel at. This expression highlights the value of experience, cautioning against offering basic advice to seasoned professionals. It's a reminder that expertise, honed over years, often needs no instruction, encouraging respect for those who have mastered their craft.