Another great read from Ellenberg! I loved the first book of his that I read so when I saw this at the library, I had to pick it up! I love the creative style of writing and the choice of content: it's the perfect blend of whimsical and informative. I genuinely feel not only enhanced in my mathematical reasoning abilities, but even more enthused about math as a research field than I was before. The bits of history of math and science intertwined are incredibly entertaining and definitely contribute to captivating my attention. I thought I had settled my little existential crisis over whether I should pursue math or microbiology as a career in favour of microbiology, but this book really reopened that can of worms, which should definitely be taken as a testament to the quality of this book! 

The thing stopping me from rating even a quarter of a star higher than 4/5 is that it isn't really for the audience it presents itself as being catered to. The title/subtitle and tone at times definitely suggest that the book is for people with little math background beyond grade school math class, but I don't really think it would be interesting for that audience. It's absolutely fascinating to me as someone who loves math and thinking about complex ideas, but I definitely understand where other reviews are coming from when they're not really in that demographic.