10 Small Details You Missed In Dune

The Bene Gesserit use the spice melange in many of their rituals and were bred to have a high sensitivity to it. Paul also has this innate sensitivity which is why, when helping the spice harvester workers escape the worm, he paused and fell to his knees. He had never been exposed to that much spice in the air and was having a vision of possible futures as a reaction.

Paul has this reaction many other times throughout the course of the movie. This is foreshadowing his prescient abilities that he is destined to one day gain by drinking the water of life or die in the process.

However, most of this is a mystery to Paul, which is why he is so surprised when he overhears Jessica speaking to another Bene Gesserit about the Kwisatz Haderach and grows suspicious of their plans. He knew he was destined for great things as the son of a Duke and spent most of his life training to be a warrior and a philosopher but as Reverend Mother Gaius Mohiam says to Paul while testing him, "you have more than one birthright, boy!"

Paul fails to realize how important he is to his mother and the Bene Gesserit.