Everything you knew about [x] is WRONG!
That kind of retroactive digital meddling is annoying enough for a movie's fans — but just try to imagine how disturbing it must be for the characters! Realizing that you suddenly remember things that you know didn't happen must be terribly disturbing, especially if they then go on to retroactively hold profound emotional meaning for you.
I guess this also explains why some comic characters are such tormented souls — take Batman, for example. After decades of constant ret-cons, he probably stumbles through life plagued by foggy visions of his parents being killed by several different, mutually exclusive, villains, as well as vaguely recalling specific events involving several partners called "Robin" he hasn't even had. I bet by now he's down to randomly calling the people who mean something to him, just to make sure they're still alive — or ever have been.
— The B-Movie Comic, #224
It wasn't the right time when we met. It wasn't the right time when we started dating. It wasn't the right time when I moved to Miami. No, it was the right time to tell me when she showed up on your front step. That about right?" With that, she stalks off. Retcons are hard on everyone, Fi.