In 1519, Cortés set sail from the Spanish colony of Cuba on an unauthorized expedition to conquer Mesoamerica with 500 men. Shortly after arriving, he scuttled the ships to prevent anyone who was having second thoughts from leaving.
As a coach, I always tell this story to players. While insane, it was this act that motivated his men to go forward - they did't have an option, they had to conquer or die in. This is an extreme example of "when you're back is agaisnt the wall fight".
