Epic of Gilgamesh Tablets IV-V

During this two tablets I had a question? Why did Gilgamesh constantly have those nightmares?  Was this like a prediction of the future? I can connect this dreams to real life though this will sound crazy, some dreams I have actually happen. They are not big dreams like for example getting a car, becoming a Hollywood star, etc. They are much smaller things. An example could be being in a classroom with a friend. This quest Enkidu and Gilgamesh is very similar to the one Bilbo Baggins and his companions did en the book The Hobbit. Huwawa is similar to the dragon in The Hobbit because he was the guardian of cave and he was  invincible, and only a strong person could defeat him.