If you're at all interested in those phrases every language has that don't translate exactly, like "the buck stops here" or one of my personal favourites: "as nervous as a long-tailed cat in a room full of rocking chairs" this might be a book you'd enjoy. It's a glossary, of sorts, categorising different idioms of the world - subjectively chosen by the authors - by varying subjects: food, national identity, animals, etc. Each entry is translated to English, explained and a brief history of its origins discussed, if the origins are known.
A great book to pick up periodically, or used as a reference.