Sombrero Wearing Dinosaur Narration

"The nightmare played on his head all over again like someone just pressed the rewind button and played it again from the beginning."

Rewinding.

The protagonist has nightmare. He wakes up and sees a dinosaur. The dinosaur says that they'd been friends, they play together, and form a friendship. He goes to school, comes home, and different scenarios occur. The dream plays out slightly differently every time he comes home but no matter what:

The protagonist wakes up in a sweat and sees a dinosaur. And it's looping like that, maybe forever. Rewinding in the protagonist's head.

The story would then be kind of silly because it's the dream of a child. Almost certainly a child that is not quite normal, but still, a child.

The ending is where the horror solidifies. "I need a drink" implies that the narrator is now a legal adult. Perhaps this character has been having the same nightmares again and again since childhood. Rewinding in his head and causing him madness.