In The Epic of Gilgamesh, why does Gilgamesh seek out Utnapisthim?

Gilgamesh is distraught over the death of Enkidu. He is forced to face his own mortality in the
death of his friend. Seeing that someone equal to himself in physical strength could succumb to
death, Gilgamesh is shaken to his core. He seeks Utnapishtim "whom the gods made
immortal." He wants to ask him "how he managed to...