Ultimately, Gilgamesh is not a good person, and this lack of morality made the “hero” less favorable and therefore not as interesting to read. Gilgamesh is driven by selfishness, an obsession with fame, and reckless behavior, all of which are exhibited multiple times throughout the epic.
When Gilgamesh is first mentioned, it is because of the prayers of the citizens of Uruk. He terrorizes his subjects, slaughtering and raping, which results in the creation of his double Enkidu. After a wrestling match between the two (caused by Gilgamesh almost raping a bride), the newfound friends embark on a quest to slay the monster Humbaba, despite pleas from the city elders and Enkidu to leave the monster alone, quoting that the Gods have placed him here for a reason, and despite the monster eventually begging for his life. This unprovoked brutality for fame is disgustingly selfish.
After defeating Humbaba, Gilgamesh is romantically approached by the goddess Ishtar. He rudely rejects her advances and insults her. This reckless action causes the spoiled goddess to release of the Bull of Heaven onto Uruk, killing hundreds of men and eventually killing Enkidu. Gilgamesh is distraught that his friend is dead, but he is even more distraught to find that death will eventually happen to him too, and so embarks on another journey to find the secret to immortality not for the good of humanity, but for his own gain.
Gilgamesh eventually finds and speaks to the immortal Utanapishtim, whose arguments for the advantage of a mortal life he ignores. Utanapishtim tells Gilgmesh of a plant that can make him young forever, which Gilgamesh enthusiastically finds until it is stolen by a snake. Gilgamesh eventually returns to Uruk, comforted by the fact that he will still “live on” through his legacy of the great wall.