In The Epic of Gilgamesh, why does Gilgamesh want to find Utnapishtim?

follows the course of the hero's journey twice. In the first iteration of the cycle, Gilgamesh
meets Enkidu. 

Enkidu is more than just kin to Gilgamesh, he is a kindred
spirit and functions as an element of conscience for the unruly and proud king. The journey for
Gilgamesh in this first iteration of the hero's quest is one that we might characterize as being
concerned with achieving adulthood or realizing one's proper place in the social world.
Gilgamesh is half-god and so his limitations are not the same as the limitations of his
subjects, the citizens of Uruk. 

His early bad behavior is an expression of
adolescence, to phrase the situation in contemporary terms. Gilgamesh does not know right from
wrong and tests his limits incessantly. Enkidu's arrival tempers Gilgamesh and, ironically, the
wild man Enkidu serves to socialize the king. The subsequent journey into the woods to slay the
monster there functions as a proving ground, as it were, for the newly adult...