è l'uovo di Colombo

Literally “it's the egg of Columbus”, in reference to an apocryphal episode according to which no one was able to make an egg stand on its tip but Christopher Columbus, who did it by just tapping its base to make it flatter. Columbus' solution was the simplest one, but he was the only who had thought about it.

è l'uovo di Colombo

1. (idiomatic) it's as plain as the nose on your face; it's extremely clear and obvious.

• chiaro come il sole
• lapalissiano