Columbus being at a party with many noble Spaniards, where, as was customary, the subject of conversation was the Indies: one of them undertook to say: —"Mr. Christopher, even if you had not found the Indies, we should not have been devoid of a man who would have attempted the same that you did, here in our own country of Spain, as it is full of great men clever in cosmography and literature." Columbus said nothing in answer to these words, but having desired an egg to be brought to him, he placed it on the table saying: "Gentlemen, I will lay a wager with any of you, that you will not make this egg stand up as I will, naked and without anything at all." They all tried, and no one succeeded in making it stand up. When the egg came round to the hands of Columbus, by beating it down on the table he fixed it, having thus crushed a little of one end; wherefore all remained confused, understanding what he would have said: that after the deed is done, everybody knows how to do it; that they ought first to have sought for the Indies, and not laugh at him who had sought for it first, while they for some time had been laughing, and wondered at it as an impossibility.

https://en.wikipedia.org/wiki/Egg_of_Columbus