This is *not* exactly what you asked for, but it sounds like something that might "entertain your mind". There's "God Created the Integers". It's a compilation of some of the most influential papers and books in the history of mathematics, from Euclid to Turing, translated to English (where necessary) and with expressions rewritten in modern notation (where appropriate), with commentary by Stephen Hawking. It's over 1300 pages, so it would keep you occupied for a while. And it's definitely not a "pop" book.