The best startup book I’ve ever read that isn’t marketed as a startup book

The book is called 138 Dates and you'd be forgiven for thinking it's a dating book, and it is, kinda, but what isn't mentioned is the wealth of startup advice also contained within its pages.
The book is written by Rebekah Campbell an Australian entrepreneur who documents her journey of finding love while also trying to run a startup. She is the current co-founder of app Hey You, formerly known as Posse.

Because the book isn't primarily designed as a startup advice book, it doesn’t sugarcoat or hide anything. The overarching message is that work (of any kind) isn’t in isolation from the rest of your life and it's this that makes the book so valuable. You will not believe the brutal honesty found within these pages from her own board of directors wanting to put someone else in charge when her team show a vote of no confidence, to having to choose between putting the last of her savings into her fledgling business or paying to have her eggs frozen so she can have a baby at a later date.

What I found most valuable:
The discussions she has with Canva.com founders – Interestingly, they didn’t bring a tech co-founder on board for a long time and were already successful at the point they did.
The discussions she has with Beat the Q founder, who ends up becoming her co-founder and they rebrand her app.
Tips from investors
Tips from mentors
Bootstrapping advice
A first-hand look at raising venture capital (what the meetings look like, questions asked etc.)
Managing difficult employees - she has a lot of dissent within the ranks
How to manage dating and relationships while also starting a business

I made more notes from this book than I had from any startup book.

Also, she had a column in the New York Times several years back, documenting her business growth which was very popular and you may be able to still access it online.

Overall, this book made me realise that there are hidden nuggets of business wisdom in places you don't expect. So, don't just stick to the places you expect to find the advice you're looking for.

What’s a good book you learned business advice from that isn’t marketed as a business book?