don't teach your grandmother to suck eggs

don't teach your grandmother to suck eggs

An older person is wiser and more experienced and worldly than a young person may think—thus, the older person does not need to be taught. I may be 70, but I've been using a computer since before you were born! Don't teach your grandmother to suck eggs, sonny!

See also: egg, grandmother, suck, teach

Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.