Where is the good life? Does it lie with fame? Wealth? Ease and relaxation? World travels and adrenaline thrills? Indulgences and pleasure? I'd wager, given enough time, any one of these would eventually cause boredom and discontent. Indeed, for some, the time it takes to become discontent may take longer, but I'd wager eventually any person would not be fully satisfied with endless fame, wealth, ease, relaxation, travels, thrills, indulgences and pleasures.
Marcus too, tried a life of logic, wealth, glory and indulgence and was never satisfied. He finally was convinced that satisfaction and contentment was in living a life according to nature.
What does a life lived according to nature look like? It is the application of the discipline of assent (we don't give into impulses; rather we meditate and work to widen that gap between impulse and thoughtless action). A life lived according to nature is a life of virtue and pursuit and attainments of excellence of character (arete). Virtue is the sole good; the virtues being wisdom, justice, temperance and courage. These virtues and principals are what ought to govern our impulses to action. Furthermore, it is a life lived in service to others (social duties in the application of the discipline of action). And lastly it is a life that accepts that God, the Gods, Fate or the Universe sends to him or her. It is a life in which he or she truly loves his or her fate.
(see also Citadel p. 270)