Gilgamesh's demigod status makes him more powerful than other people, but it also alienates him from them. At the beginning of the poem, he is a tyrant. He uses his power to bully, rape, and kill. His demigod position alienates Gilgamesh not only from human beings, but also from the gods themselves. Unlike the gods, he is not immortal, and he will one day grow old and then die.

Gilgamesh's alienation is alleviated when he befriends Enkidu, who is also a demigod, though he is only one-third divine in origin. Being more human than god, Enkidu is closer to the people Gilgamesh abuses and therefore confronts him about this. What starts out as an antagonistic battle becomes one of the deepest friendships in world literature. The love they share makes Gilgamesh nobler and fairer, since he now has someone to challenge his behavior when he acts out of line. When Enkidu dies, Gilgamesh is lonely once again, and this prompts his quest to live forever.

This internal conflict between Gilgamesh's divine power and his human weakness reflects the poem's central theme of accepting mortality. For all his power, Gilgamesh will eventually die, like any other human being. In order to become whole, he must accept his mortality and the human part of him that will not always have access to godlike strength.