Once there was a simple Buddhist monk by the name of Ryokan who lived in perpetual retreat in a small hut at the base of a mountain. One evening a thief broke into his hut only to discover it was empty. Ryokan returned and caught him. "You have come a long way to visit me," he told the prowler, "and you should not return empty-handed. Please take my clothes as a gift." The thief was bewildered. He took the clothes and slunk away. Ryokan sat naked looking at the full moon. "Poor fellow," he mused, "I wish I could give him this beautiful moon, too."
Some might say that Ryokan was letting the thief take advantage of him by giving him his clothes. But the point of the story was that Ryokan was so compassionate and so non-attached that he genuinely didn't mind giving the thief his only possession - his clothes. This is best expressed in the words of Shantideva, who said:
"All those who suffer in the world do so because of a desire for their own happiness. All those happy in the world are so because of their desire for the happiness of others."