This scene blew my mind as a kid

When I was a kid watching this scene, loads of questions were going through my mind like “How come Vader was on Dagobah?” “How did Luke beat him so fast?” “Why is Luke’s face in the helmet??” “How did Vader make it back to his Star Destroyer so fast?” “Did they have to sew his head back on?” Because back then I had no concept of what visions were