WARNING! Spoilers for Dune.
What is the meaning behind the opening message of Denis Villeneuve's David Lynch's 1984 sci-fi movie and the 2000 SyFy mini-series. Villeneuve's movie is a true sight to behold, with the movie also diving into metaphysical and esoteric concepts relating to the destiny of its protagonist Paul Atreides (Timothée Chalamet).
The film opens with the caption "Dreams Are Messages From The Deep," but this isn't given any significant explanation or context. At the same time, Dune involves many unexplained visions in the mind of Paul Atreides, so it's safe to assume that the movie's opening message relates to that. The question then is: what do the opening text and Paul's visions mean together?
The movie heavily positions Paul as becoming the prophesied figure known as the Kwisatz Haderach, so Paul experiencing bizarre, unexplained visions certainly fits into the framework of his story. It also may refer to the endless sand dunes of Arrakis itself as "the deep," with some of Paul's visions coming after he is exposed to the mind-expanding spice melange, which is a precious resource mined by House Harkonnen and later House Atreides from the depths of Arrakis. What's even more interesting is what Paul's visions actually show him.
Paul's visions don't actually show present-day events happening in Dune, but are instead flashes to Paul alongside Chani (Zendaya) and the Fremen people. Paul is clearly seeing visions of the future, or at least of the possible future, with one showing him being stabbed. In a movie as intricate as Dune, classifying these visions as "dreams" certainly fits the very surreal feeling of what Paul experiences when he sees these unexplained flashes into the future, and the film's opening caption could, in fact, be referring to both Paul and Arrakis as "the deep."
With Paul's visions emerging from the deepest parts of his subconscious mind, this indicates it as a depth from which his "dreams" are arising. Meanwhile, with Arrakis as the source of melange, his visions are made more vivid, and melange, as the tool that makes this possible, deriving from the literal subterranean depths of Arrakis.
Even for only adapting the first half of Herbert's novel, Dune is a remarkably dense and thematically layered sci-fi movie. A lot of the chatter has been centered on the prospects for Villeneuve to tell the second half of the story should the Dune become a box office success (though its HBO Max performance is the real bar in that regard.) Hopefully, Dune's story continues and audiences will be able to take a further dive into the depths of both Arrakis and the mind of Paul Atreides.