The thing about Hercule Poirot (yes I know what book this is) is that beneath his pomposity and performative narcissism there's actually a nice person. The impression I get of Jane Marple is almost the opposite. She pretends modesty and concern, but she's not nice, and she's ready to take every opportunity to show people how incredible she is. And part of that is the way people react to them; Poirot is seen as absurd and he's happy for people to see him as such, even playing into that impression for the sake of getting people to let their guard down. In this book, other characters literally will not stop talking Marple up, both to each other and to her. She makes token protests while clearly loving it. And that's why I don't like her.

Also the mystery in this book was merely okay. It wasn't bullshit, but it didn't make me go "oh my god, how did I miss that?" or "oh that's clever" I just sort of thought "Oh. Yeah, I guess that's plausible."