Adding my own two cents:

Fifteen Hours by Mitchel Scanlon - a story of a guardsman on his first deployment. It's 40k, so you know it's a tale of merrymaking and sunshine. I was afraid people oversold this book, but it turned out to be pretty dang good. TL;DR: a Vietnam war movie with an arc from FNGs to body bags, but with laser guns and space-orcs.

Chivalry and Courtesy: Medieval Manners for a Modern World by Danièle Cybulskie - it's the same author who wrote How to Live Like a Monk -- mentioned in the last thread -- who this time takes on manners, grooming, and upbringing of children. It's... hm. I didn't find it to be as good, but probably because I didn't learn all that much new stuff from it? Wholeheartedly recommend it, the substance is there, it was just a tad too introductory to someone who read some of the sources beforehand.

A Short History of Nearly Everything by Bill Bryson. You know what? It's the same problem as with Chivalry and Courtesy: I'd love this book 10-ish years ago, but now it felt like marathoning 12 straight hours of something like SciShow on youtube (neither a channel recommendation nor lifestyle idea). There's a lot of trivia on history of science that I'll probably struggle to recall in three months, and a more than a couple things that are no longer correct, but I don't regret picking it up or recommending if that's your jam or didn't do well in the science classes.

De Generibus Dicendi (On the types/kinds of speeches) by 'Iacobus Gorski' (Jakub Górski, or Jacob Mountain-like if you're into silly translations) - It's one of the first Loeb-inspired (Latin text on the left, Polish on the right) books published here, and a real treat. It's an overview of ancient and contemporary (XVI century) rhetoric, and a bit of a instructor's handbook on the topic.

I've also tried to go through Brave New World by Aldous Huxley, but it's been a fucking slog even in audiobook form.