I was just about to click on this and suggest Sapiens. It's one of those books I have on my shelf as I know I will read it again. I especially like Harari Yuval Noah's attitude towards speculation, and those that try to impart today's beliefs on what our ancient ancestors must have been like.

I like all history, but pre-written history is starting to fascinate me more and more. The fact that we have no clue, and will never know unless somehow time travel is invented is what draws me to it. Something where all inferences are ultimately baseless as even nomadic cultures today have ultimately been impacted by all the past events leading to our current global society. We may eventually figure out the wonders of the universe, and quantum mechanics may well be replaced by an even more elegant solution. Travel to distant stars. All that is possible in the future. But we will never truly know what our ancestors were thinking 70,000-12,000 years ago on the dawn of that cognitive revolution and our great dispersal. When I read the summation of those chapters at the beginning you begin to understand the brilliance of Harari's writing style.

I think the best kinds of books are the ones that impart knowledge that make you put them down for a few seconds every now and then to let what you have read just sink in :). But mainly act as a catalyst for introspective reflection whilst reading it as a way of gaining insight on the world's mechanisms, and cause you to constantly challenge your place within them.