Don't teach your grandmother to suck eggs

Origin

In a time when simple domestic skills were crucial for survival and economy, grandmothers, having lived long lives, were undoubtedly masters of everyday tasks. Imagine the absurdity of a young person attempting to instruct an elderly matriarch on something as basic as preparing an egg—a skill she would have performed countless times. Whether delicately cracking it open or, more colloquially, 'sucking' out its contents with practiced ease, her proficiency would be beyond question. The vivid image of a novice presuming to impart wisdom on such a fundamental life skill to one who has perfected it through decades of experience solidified the phrase's enduring message: never offer advice to a seasoned expert.