I loved this book. It took me a long time to read because it (literally) made my brain hurt while reading it. The concepts are beyond my level of math, so they were challenging to my thinking. They are presented so that the average person can tackle quantum physics and subjects more complicated than the proverbial rocket science or brain surgery.
This is a great book, written very well, that brings the work of brilliant scientists to the "normal" person's life.
Considering that I haven't taken a physics class since high shcool, I started this book expecting to follow only a minority of the information presented. However, Hawking does an excellent job explaining complex mathematical theories in the most basic of terms.
Even so, the book did require my undivided attention and still I couldn't follow every single idea. (For example: it was difficult for me to wrap my mind around imaginary time and to think in four dimensions.)
I absolutely loved this book (so much, in fact, that I read it twice) and can't wait to read more from Hawking. I recommend this book to anyone interested in understanding the universe in which they live ranging from the extraordinarily vast (general theory of relativity) to the extraordinarily small (quantum mechanics) and the search for the Theory of Everything (uniting the two theories in a quantum theory of gravity).