I read this book last year - at the tender age of 17. When I bought it, I presumed it to be pretty much the same type of book as Eli Maor's 'To Infinity and beyond' - but it wasn't. To be able to read and understand this book, you need to be a capable mathematician - or be willing to let large chunks of it pass over your head - as I did. Having said this, there are plenty of interesting topics covered in the book - and it opens your eyes to lots of new areas in maths which you never knew even existed. If you're a budding mathematician then you must read this book - though I'd leave it until you're at university.