I'm a big fan of this book because it's written by someone who has started a major company (Paypal).
Zero to One is a short read, and Mr. Thiel takes an objective look at what makes startups successful. My favorite takeaway from the book was recognizing the value of companies that take vertical risks. A vertical risk is creating new technologies for society instead of making existing ones better.
Siddhartha is a short read by Herman Hesse. It addresses that the only constant in life is change. Warning, the river chapter may make you tear up!
Sapiens got me started on reading books. It's an amazing read that gives a comprehensive look at where we come from, and how societal structures were built. The concept of shared fictions has been influencing my decision making to this day.