The great Roman statesman and general Julius Caesar had some pretty extreme ideas about motivation. Soon after landing on the shores of Britain, he marched his legions to the very edge of the Cliffs of Dover. Then he told them to gaze down into the waters below.

What they saw shocked them. Their own ships were set ablaze and were sinking on Caesar's orders. With no possibility of retreat, they soon did what they had to do. They conquered Britain.

Now, Caesar's methods might be a bit morally questionable, but they do illustrate an important truth.

It's amazing what we can do when we don't have a choice. According to a poll conducted by ESPN, the greatest World Series moment of all time was Kirk Gibson's home run in Game 1 of the 1998 series.

Although he was playing with injuries to both legs, the Los Angeles Dodgers put Gibson in as a pinch hitter when the game was on the line. He hit foul after foul, his legs hurting so badly it was difficult to get back on his feet.

Then, he did it. He hit a home run, just as the Dodgers coaching staff predicted.

How did they know? It was his bad legs. They knew he'd hit a homer because there was no way he could run to first.