Why is Grandma so good at sucking eggs?

The subject says it all really. What’s the origin of the common expression that attempting to teach someone about something they already know is like “teaching your grandmother to suck eggs?”

First, someting funny from a Star Trek fanfic I found while searching for the answer:

“My mother had a saying for everything. My first lessons in the adaptability of the human species came when she could fit her sayings to almost any Vulcan situation. I remember once, when I was almost eight and very full of myself, I tried to teach her how to control her emotions. She listened to me gravely, and then said, “Spock, don’t teach grandma how to suck eggs.” Then she got up and left. It was many years and many humans later before I figured out what she meant.”

– Without A Spark [R, gift challenge, K/S, TOS] Spock agonizes over the situation. Second Place, TOS/TNG Christmas Story, 1997 Alt.Startrek.Creative Awards.
For the origin this is the best so far:

“To teach one’s grandmother to suck eggs – To offer needless assistance; to waste one’s efforts upon futile matters; especially, 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 teach Minerua, was a prouerbe, for which we sai: Englyshe to teach our dame to spyne.’” That last bit was about an expression, don’t try to teach a dame to spin.

– Funk, Charles Earle “A Hog on Ice and Other Curious Expressions”. Harper Collins.

Your old pal Stinky Wizzleteats knows.

(Those who get the reference are my friends forever.)

Even if they’re an eediot?

Joy!

Because she has no teeth and has to eat somehow. No teeth are needed to suck the innards out of an egg.

The French equivalent, as far as I am aware, is ‘The goslings want to lead the geese to pasture’.

My copy of ‘Brewers Dictionary Of Phrase & Fable’ fails to give the origin, but my money is on *Eric Cantona.
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*Former Manchester United soccer legend, now a big cheese in beach football.

But did you know that the picture on the record jacket was of Burl Ives and the sampls of him talking were taken from the movie Big Country including the “I told you i’d shoot… why didn’t you believe me!”

I can’t believe another human being owns this book.