In the time of extended life-spans, when Methuselah like ages of a thousand or more years was normal, and death seemed to take a vacation, so too did ambition. The quick and the dead came to refer to those quick un-augmented who came and went in under a hundred years, and those, ironically, who lingered on, as much dead as alive, with no urgency, for there will always be enough time to make amends, attain a goal, reinvent themselves dozens of times, or languish under the harsh master of the drug du jour.
This, then, provides the stage for Sloth, a particularly long-lived individual, clothed in years and ancient of days. In his youth, up until the age of perhaps two hundred, Sloth fancied himself something of a daredevil, and reveled in the rush of adrenalin from pushing himself to more and more dangerous activities, from space jumping (leaping from one space craft to another without the aid of a protective suit) to enduring flames for extended periods of time to just about anything that endangered his life until he realized that it was all just maths, and as long as he made the right calculations, nothing could or ever would go wrong, and the thrill of the stunt faded.
This ushered in his blue period when he sought to explore his artistic self, dozens of years studying the masters until he could copy any of them and again, the meaningfulness faded. Of what import were the masters if he could be as good as any of them in only a few dozen decades of effort and attention. Still, something rankled him