She was a pretty terrible person in her previous life and she isolated herself and pushed everyone that tried to care for her away, and then she went ahead and cheated on her husband because she was lonely. When her poor husband died on the battlefield after a conspiracy, she got exiled from the territory for being a cheater, which is honestly deserved, and her lover who was manipulating her also abandoned her. She ended up homeless and in extreme poverty, and at the death's door she expressed to God that she didn't want her life to end this way and thus somehow regressed.
Now you would assume that upon her regression she would change her ways, but not really. Her personality didn't change much, she just lost her immaturity and extreme spending habits. Because she was a cheating bitch she accused the count of cheating on her and kept at it for like 2 dozen chapters, even though the count is literally the most inexperienced virgin in the freaking Kingdom and it's super obvious. She never felt remorse for cheating on her loyal husband in her past life, and kept misconstruing most of his actions as "evil" for a couple dozen chapters, even when everyone around her was telling her otherwise.
That's my problem. While her circumstances in her first life were unfortunate, she kept ruining her life over and over and over. But overall I'd say that she deserved to die a miserable and lonely death. If she was a side-character in a different novel that met such an end I wouldn't even blink an eye. But now I'm supposed to cheer for this girl who didn't even change that much after all the suffering she went through?
The other thing is that 95% of the male cast end up falling for her. Even the piece of shit prince that only ever manipulates people and is her husband's killer in the 1st life falls in love with her after meeting her briefly twice. And keep in mind that she didn't even interact with him that much, she only politely rejected his weird advances.
Finally, the worst thing is the community reading this crap. I saw countless comments saying that her cheating was fine because she was lonely in her first life. Like, seriously? Her husband tried to reach out but she was downright neurotic around him and kept pushing him away when he never as much as raised his voice against her. She was lonely because she wanted to be lonely! How is it okay to cheat because of that!?
Anyway, that's my problem with this one. I don't understand how it's so highly rated, especially on forums like Reddit. I only ever hear praise about this one. It's insane.
