In before it turns out that he's going to die, or at least seem dead, soon, and the counter counts the days before she commits suicide because of their relationship.
I really want the prince's pov of this entire debacle. I can't imagine that he isn't aware of the necklace's effects if he's been reading her mind the entire time. Surely he's at least curious about all the weird stuff she's thinking.
Okay, that one's on her. She had him on the cusp of realization, then shot down her own chances because she's too proud to look vulnerable to him. Dense MC-kun aside, her mixed messaging is asinine.