This is what I believe has happened to Judith:
So MC had died of old age as a Korean in her first life. She then reincarnates into another life, becoming Judith. Luca, her nephew used the goblet of wishes to turn back time. As such, time rewinds with Luca obviously remembering his future self, but so did Judith. However, for Judith, as the memories of the future surfaces into young Judith, it caused her first life persona to somehow dominate her current life persona as Judith. This led her to have a split personality of some sort, where her first life persona became her sole identity, whereas, her current life identity as Judith transformed into nothing more than some “character from a novel she once read”.
But here’s the thing. I’m assuming that Judith’s soul couldn’t handle the memory transfer, from future Judith to past Judith (maybe because her soul is probably unstable as she is someone who remembers her first life). As such, gaps in her memory were probably formed, and add onto the fact that her first persona gained dominance over her current identity simultaneously (and the fact how our brain naturally/subconsciously tries to make sense of things), this led the mc to where she was in the first chapter. Someone “who died from a car crash and transmitted into a character into a novel that she once read”. All in all, since the first chapter she’s been in a confused personality state with fake memories due to memory gaps.
In fact, one sign of this is found in a previous chapter. The mc was trying to remember something regarding “Judith and the story” but then realized that she didn’t know the name of “the story”.
she didnt gain her first life persona, her change in treatment of luca was actually because of her regrets before regressing. so she still have og judith personality, but with now "id treat luca better" cos it was her dying wish. her modern self memories were just filled in the gaps since she technically still have those, just pushed back. since shes supposed to forget after regressing, like u said, those memories were pushed forward since they were not part of the og judith memories.
MY HAND IS ITCHING FOR SOME BITCH SLAPPING