In The Epic of Gilgamesh, Gilgamesh goes on journeys for renown and immortality, which results in socialization and maturation. He does not believe others when they tell him that immortality is not possible for mortals. So, with his companion Enkidu, he goes abroad into the world in search of everlasting life. Gilgamesh's quests go not just to the known world of Mesopotamia, but also to the seas and tunnels beyond the world's end.
Gilgamesh is the mightiest of ancient kings. He rules as a tyrant, ignorant of his duties and bound by arrogance, all the while exhausting local youth and being disrespectful to the maidens. His ultimate objective in life is to gain immortality; in the past he has tried by building the walls of Uruk, a great rampart, and a temple of the blessed Eanna. Gilgamesh realizes that his works inside Uruk will not gain him immortality, and he decides that he must take his adventures outside the walls of the city.
Each of Gilgamesh's journeys plays an important role in progressively humanizing him. On Gilgamesh and Enkidu's journeys, Enkidu enrages the god Enlil, by commanding Gilgamesh to kill Humbaba; he also threatens the goddess Ishtar. Due to Enkidu's behavior, he dies. Gilgamesh's grief for Enkidu is his first step towards humanization. After bitterly weeping for his companion, Gilgamesh goes on a quest to find the god Utnapishtim, still in search of immortality. Along his journey he meets other gods who encourage him to turn back and live his life to the fullest in Uruk. Gilgamesh is strong willed and will not give up. He finally meets Utnapishtim who stresses and proves to Gilgamesh that no mortal can obtain immortality. Although, Utnapishtim does tell Gilgamesh about a plant belonging to the gods, it is underwater and will restore youth. Gilgamesh goes into the water, which symbolizes rebirth. His whole being is transformed and he is fully humanized.