Celtic Philosophy - The Emerald Ring

Once upon a time in Ireland, there was a King of Ulster called Feanach, and he ruled with a wise and goodly hand. His kingdom was happy and prosperous; yet, Feanach believed that something was missing. He pondered much on the matter, but he couldn't quite work out what it was that the people needed to make them truly content. He was walking through the woods one day, when out of a rowan tree sprang a leprechaun.
'Good day to ye, Lord King,' said the leprechaun. 'You have a sad and worried face upon ye. What would it be that is troublin' ye?'
'I don't really know,' said the King sadly. 'My people seem happy. Yet deep down within me, I know something is missing. There's an emptiness in my heart.'
The leprechaun looked at the king with interest. 'There are not too many who'd be realisin' that prosperity is not all there is to life,' said he. 'I tell you what, Lord King. I'll give you a treasure that will make you wealthy beyond all your dreams. But you won't learn its true value until you stand with nothing at all in this life, when you have lost everything but the ring you'll be wearin' on your hand.'
And the leprechaun placed a ring on the King's right hand. 'When all of life is against you and you stand friendless and alone, prise the emerald from this ring, and you will find a treasure beyond all price.'
The King thanked the leprechaun, and wore the ring back to his castle. Almost immediately, there was a different atmosphere in the Kingdom. Not only were people wealthy, but they were content, and their hearts were at peace. And so it was for some years.
But then invaders came from the north seas, and from the south and the east, and the land was ravaged and the army killed. Those people who were not murdered by the invading hordes died of disease or fled. At last, when the wild tribes of killers had left and burned all the Kingdom, the King was alone, deserted, in the ruins of his kingdom. He had been wounded; he was almost starving; he was ill and feverish. He felt responsible for the deaths of his people. He had nothing. He sat among the ashes and wept with despair. He was ready to kill himself, so hopeless did everything seem.
Then he remembered the emerald ring. Wonderingly, he looked at his right hand. The ring was still there, gleaming through the dirt and the blood. The King removed it, and recalled what the leprechaun had said. He found a piece of rock to chisel the stone from its setting. The emerald dropped to the ground and rolled away. In the cavity lay a small scrap of paper.
The king sighed. So this was just another leprechaun trick, he thought. Another cheating game of fickle life. He withdrew the paper and carefully unfolded it. And immediately he took heart. For written on the paper were these words:
"This, too, shall pass."