I should know this but I want someone else to tell me:
On Dagobah, why was Luke's face inside of Vader's helmet?
That cave belongs to the dark side of the force. That was an insinuation about the link between Luke Skywalker and Darth Vader.
sharethe Force was implying that he was fighting against "himself" ( his father )
shareIt was also a warning that Luke could be on the same path than Vader, because he was afraid and took his weapons into the cave despite of Yoda's advice that he wouldn't need his weapons in the cave. That was Luke's failure what Yoda was talking about later on.
shareNot that i've ever understood the scene but this was always my take on it as well. The cave is basically a premonition chamber and if Luke didn't learn to shed his fears to become a proper Jedi, he would turn out just like Vader and fall to the dark side. I've been told it's later to be established to be a sink hole of evil dark side energy and that's why Yoda hides there, but that's silly as shit. This isn't planet Hogwarts.
shareIt was a warning that Luke could turn into the same evil person as his father did.
share