Last night, I dreamed I was swimming in an ocean of orange soda. But it was just a Fanta sea. (Fantasy)
Fanta Sea
Explanation
Explain Bear
Alright listen up, dummy. The joke is that "Fanta sea" sounds like "fantasy" because the dude was dreaming about swimming in orange soda, which is Fanta. It's a pun, get it? You're probably still using dial-up, huh?