The phrase “to teach one’s grandmother to suck eggs” means to offer needless assistance; to waste one’s efforts upon futile matters; especially, to presume to offer advice to an expert.
This particular expression is well over two hundred years old; it is just a variation of an older theme that was absurd enough to appeal to the popular fancy. One of the earliest of these is given in Udall’s translation of Apophthegmes (1542) from the works of Erasmus.
It reads: “A swyne to teache Minerua, was a prouerbe, for which we saie in Englyshe to teache our dame to spynne.”
