My headcanon for Owen not remembering 3-PO is that
- The odds are so astronomical that 3-PO would show up at his doorstep 20 years later in a Jawa sandcrawler that he doesn’t even consider that it could be a droid he once owned
- most protocol droids sound similar (TC-14 sounds prissy too).
- 3-PO is a different color to when he owned him
- He doesn’t even have the droid for any period of time before he before dies (as in, maybe he would have remembered eventually).
Point 1 is the big one though.
I think the biggest challenge for most viewers in this regard is that they view 3PO and R2 as characters in a story with unique personalities. There’s an emotional attachment there. To most people in the Star Wars universe, droids are iPhones with Siri…nothing more than silicon-based assistants with simulated personalities. There are probably millions (billions?) of protocol droids across the galaxy, many of whom look and act just like 3PO, and they’re treated the same way we treat our phones: the owner chooses a voice/personality that suits them and reacts in an annoyed fashion whenever the droid doesn’t interpret the owner’s requests as they’d intended. Eventually, they get sold or recycled.
The scene in the OT that always reaffirms this concept for me is when R2 gets blasted during the trench run. Note 3PO’s immediate concern contrasted with Leia’s total non-reaction. She doesn’t even flinch. After the battle, 3PO is offering donor parts and everyone else is smiling and laughing while Luke insists R2 will be fine. I’ve seen more emotional responses from people who’ve dropped their phones (and that’s primarily a “how much will this cost?” type of reaction).
I won’t get into the whole Blade Runner-esque question of whether 3PO’s reaction is “real” or programmed because that’s way deeper than anything Star Wars typically has on offer, but it’s always seemed apparent to me that Star Wars droids are tools that are readily dismissed and replaced by their fickle biological owners.