War gives no opportunity for repeating a mistake

The Trojan Horse is a tale from the Trojan War, as told in Virgil's Latin epic poem The Aeneid and by Quintus of Smyrna. The events in this story from the Bronze Age took place after Homer's Iliad, and before his Odyssey. It was the stratagem that allowed the Greeks finally to enter the city of Troy and end the conflict. In one version, after a fruitless 10-year siege, the Greeks constructed a huge wooden horse, and hid a select force of 30 men inside. The Greeks pretended to sail away, and the Trojans pulled the horse into their city as a victory trophy. That night the Greek force crept out of the horse and opened the gates for the rest of the Greek army, which had sailed back under cover of night. The Greek army entered and destroyed the city of Troy, decisively ending the war.

http://en.wikipedia.org/wiki/Trojan_Horse