When Nolan lies to the audience (either brother), he doesn’t really lie. Instead, Nolan uses a three-step structure to pull off a plot twist.
PART I: THE STATEMENT:
For this topic, we’re going to use the Cobb wakes up on the beach scene from Inception, so if you haven’t watched Inception, spoilers ahead! The shot of Cobb waking up on a beach is used 5 times in the movie, but there are only 3 occurrences we need to talk about.
The movie begins with a statement, with an out-of-context shot of Cobb waking up on a beach. Think of this as if you were given a line from the middle of a story without you knowing anything about it. You can’t say if this is true or false, only that it has been told to you.
Then Cobb is taken in front of an older Saito, then the movie intelligently switches to a younger Saito without you realising the switch, as the movie goes on, you forget the opening scene, then Nolan makes you remember it with a Half-lie.
PART II: THE HALF-LIE:
This happens when Cobb tells the story of Mal to Ariadne, in the first level of the heist. He tells Ariadne the half-truth about them, how they got stuck in limbo and then came out. The limbo scene begins with Cobb on the beach shot. However, he leaves out a lot of important parts.
Think of the half-lie as if you were to read a story, but only alternate lines. In a normal story, this wouldn’t make a lot of difference, but in Inception, where most things are not real, it is possible to get a very different sense of what’s happening than the truth of the situation.
So, at this point, we know that there is an older Saito and that the beach is in the limbo world.
PART III: THE TRUTH:
This takes place when Mal tells the whole story to Ariadne, finally giving us the truth. The truth that Cobb knew Inception was possible because she was the first person it was done to.
Then we get the final piece of the puzzle in the form of a dialogue when Cobb says “Saito is dead by now. That means he’s here. I have to stay here and find him”.
Then we go back to the real truth of the beginning scene. Nolan has already given us all the pieces of the puzzle. In 3 parts, he tells us that there is an older Saito, the beach is in the Limbo world, and that Cobb has to bring back Saito from the limbo world.
CONCLUSION
Inception’s beach scene is one of the many examples of telling only the half-truth to the audience in Nolan movies, the same technique was also used in Memento and The Prestige.
If you want to use this technique for yourself, try to make it as subtle as possible for the audience to get shocked when the reveal happens.