15 Infamous Movie Plot Holes (That Actually Aren't)
10. Why Did Luke Skywalker Keep His Surname? - Star Wars
The "Plot Hole": If Obi-Wan and Yoda wanted to hide Luke Skywalker from the reach of his father, why did they leave him on his home planet with the same damn surname? Wouldn't it have made sense to at least change his name?
Why It Actually Isn't: Awkward writing, sure, but not a plot hole, and one that's got quite a few explanations.
Firstly, Vader never had a reason to believe he even had a son, and even then, the mind-meltingly huge scope of the galaxy could make it practically impossible to track him down, either due to the presumed lack of a galaxy-wide phone book or the mere probability of there being many people with the same surname. Simply, there was no need for the name change.
Oh, and Anakin doesn't like sand, and probably didn't want to return to the planet where his mother was murdered, so there's that too.