We would seriously be calling up our therapist if we were having so many spookily prescient dreams. But, you know, ancient Mesopotamia was a little short of therapist—so instead, he just asks his mom. And his friends.
Okay, that actually sounds a lot like what we do.
Anyway, we first hear about Gilgamesh's dreams in Tablet 1. In one of the dreams, Gilgamesh embraces a meteorite which has fallen to earth. In the other, he embraces an axe. (Yes, we agree, these are wacko dreams.) His mother, the goddess Ninsun, interprets his dreams as a promise that "there will come to you a mighty man, a comrade who saves his friend" (1.249).
This, of course, is a revelation about Enkidu coming into the picture. But, amazingly, Shamhat also knows that Gilgamesh has been dreaming about Enkidu, "Even before you came from the mountain, Gilgamesh in Uruk had dreams about you" (1.224-225). (We really would like to know how the temple-prostitute knows all this.)
Then, there are the numerous dreams that Gilgamesh has during the journey to the Cedar Forest in Tablet 4. Gilgamesh prays to Shamash for these dreams. In fact, it seems that dreams are the primary mode of communication between gods and mortals. The events in these dreams are symbolic, but seemingly accurate.
Enkidu listens to each of these dreams, and then provides a very cheery interpretation, although the dreams themselves seem rather terrifying—featuring Gilgamesh fighting with a bull, "lightening cracking,""[raining] death," and everything turning to ash (4.95-101).
In Tablet 7, poor Enkidu—already facing illness and certain death—is tormented with dreams about the underworld. (Talk about unfair; give the poor half-man-half-beast a break.) But this dream allows Enkidu to describe in great detail all the horrors of the Underworld, which is enough to motivate Gilgamesh to go in search of immortality.
So—dreams in this epic are something like previews: they give you a taste of what's to come, and sometimes they turn out to have very little to do with what actually happens. Next time on Gilgamesh ….