An egg of Columbus or Columbus' egg, refers to a brilliant idea or discovery that seems simple or easy after the fact, the expression refers to an apocryphal story in which 1492, a Spanish-based transatlantic maritime expedition led by Christopher Columbus encountered the Americas, a continent which was previously unknown in Europe, leading to the colonization of the Americas?
Egg of Columbus:  The expression refers to an apocryphal story in which Christopher Columbus, having been told that discovering the Americas was inevitable and no great accomplishment, challenges his critics to make an egg stand on its tip.
i don't know