Eric_S said:
"You know of the rebellion against the Empire?!"
Tattooine is REALLY far out of the way in a really big galaxy. Luke is a clueless teenager. I would be more surprised if he actually knew who Anakin Skywalker was in the first place.
That's yet another indicator of how Lucas' inability to write created a giant plot hole that he was never able to SE his way out of.
In Star Wars, Luke's father is mentioned briefly, early in the film, as a story point to establish Luke as an orphaned kid living out in the middle of nowhere. Ben knew his father, had his old war weapon, and gave it to Luke.
Same for Leia. Her father is mentioned briefly as a plot device to get Ben involved, then the story moves on. The problem - and to me it's gargantuan - is when Lucas couldn't come up with a sequel, as well as rejecting the two that he asked two other authors to write.
He decided instead to rewrite the first story. Luke's father and Leia's father - two separate characters unrelated to Vader - should have never been brought back into the story, whatever direction it went in.
However, not only did Lucas bring back Luke's father as a story element, he changed him to someone who was already in the first film. He then muddied the story even further when he later tied him back into the Leia arc by making him her father too (more writer's block).
He took three established & different characters and changed them all into the same guy. Once the fans accepted that pretzel logic, he took the ball and ran with it. If you can get your audience to accept an on-the-fly rewrite that ridiculous, they'll accept anything.
Ultimately, he made Luke's father the primary character in five of the six films. Yet, as this discussion shows, it still makes no sense when you try to align it with the original story.
It's poor writing that no amount of discussion, SEs, or revisionist history interviews will ever be able to correct.