The dwarves, the children of stone, loved the stone and the riches they yielded. They toiled and sweat, straining gems and metals from the mountains, and they were content.
The elves, children of the earth, sons and daughters of the forests, loved the trees and the life found beneath them. They ran with the fauna and rested with the flora, they danced beneath the boughs, and meandered along the fields with grace and beauty, and they were content.
The men, the children of the gods, loved knowledge, exploration, and adventure. They loved to live, but somehow their love of such rich things had twisted and tangled itself seemingly beyond repair. Their love of life turned into a habit of taking and destroying it. Their love of knowledge morphed into a thirst for hidden truth and secrets best left alone. Their love of adventure changed into a desire to crush the dreams and aspirations of their kin.
Like their gods before them, the fell victim to their own curiosity, growing further and further apart, even as their accomplishments and feats seemed to bring them ever closer together. The flame of their communal nature was slowly starved, being steadily snuffed out by their growing, cancerous lusts.
The race of men was a tragic one. Their lives were short, compared to those of their elven and dwarven brethren. Their race was a young one as well, having risen up in more recent times, while the elder two had been walking the earth longer than time could even remember. Perhaps, in days long since forgotten, the elves and the dwarves had stumbled through similar such sins and learned from their mistakes. However, time was no friend to humankind, as they had but a few short years to experience all that life had to show them.
Perhaps it was for this reason that they lived so furiously. Perhaps it was because of this that they yearned to explore the world as they did, and chased after knowledge and adventure. Perhaps it was the very nature of their short lives that taught them to live while they were yet alive, and to cherish every moment. Even with all their sins, this innocent aspect of their true nature remained mostly intact; in fact, it was possibly their greatest trait.
And so they were never content, because they inherently knew that contentment was not the goal. The goal was to live, and to find all that this life had to offer; the good, the bad, the dark, the light, and all the moments in between.