system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] C-3PO’s memory is never wiped after Episode III. What changes?

What, if anything, would happen differently or would he do differently?
gpt
Assuming palpatine knows his memory is intact Luke and Leia are snatched up soon as the empire gets their hands on his memories and turned to the dark side at a young age to replace Vader.  Outside of that happening Leia would know she has a brother sooner than Return of the Jedi.  Probably would go find Luke prior to a New hope and work with obi wan to train both in the force and more directly confront Vader prior to the Death Star becoming active. Best outcome family unites to stop palpatine and the entire original trilogy never happens.  Worst case they kill Vader following obi wans instructions despite knowing he's their father and fall to the dark side.  3pos only involvement would be revealing the family relationship and where the twins are at which depends entirely on how close bail organa kept 3po to Leia or if he simply served on the tantative 4 and a new hope was Leia's first meeting with him.