The story of an English woman living in Paris after WWI. She has an investment income that supports her and she supplements that by borrowing from rich friends, so she doesn't really need to work. She spends her time eating at restaurants, dancing, drinking shots, and purchasing hookers. She's also really, really upset about how unfair the world has been to her. And then she takes out that upset on the people around her. Overall the story is a bit like _The Idiot_, but without the intelligence. Or maybe like Bukowski without the energy or the grounding in working life. Or maybe like some of the passages from Iris Murdoch, about a character completely overcome with grief, and their blind and animal sobbing and how unbridgeable the gulf is between them and the other characters.
On a personal level, as someone with a living income who frequently wakes up around midnight, the narrator was hugely irksome. If you have the money to support yourself it sort of puts a lower bound on how bad most situations can ever really be, and it makes this kind of self-absorbed whinging really annoying. Not to say that I don't do it myself! But I at least have some self reflection, and there's usually the moment of "well, I suppose on a larger scale things are still pretty ok." Sort of a reversed and positive version of this meme, a moment where your context expands. The narrator here though, she never really has that moment.