The story
From a 1707 translation by John Stevens of comical works of Francisco de Quevedo (1580 – 1645). "You would have me teach my Grandame to suck Eggs"
Etymology from Wiktionary, CC BY-SA 4.0.
don't try to teach grandma how to suck eggs
Today it means: Don't presume to give advice to those who are more experienced. Full definition →