I struggled through it 20 some years ago.
It’s not that it’s particularly difficult to understand, but it sure is difficult to read.
He didn’t read it, right?
He might have. One thing with the way that his voice system worked, is that if you already have a text file, it’s essentially no extra effort to read it aloud. Heck, he could click a few buttons to start the process, and read an entire book aloud while he’s busy doing other stuff, and not even have to absorb any of it himself.
If I recall, he read the introduction and maybe chapter epigraphs. It’s read by a Michael Jackson (not that one). It’s much easier to be absorbed when listened to. It’s available at Archive.org in MP3 format.
I’m educated as an AeroE and at one time was very good at physics and higher math. I read the Illustrated and Expanded Edition of ABHOT about 12 years ago while in my lazy late twenties. At the time I was pretty stale on my education and very out of practice at math, yet I still finished it and understood almost all the concepts if not every detail about their origins and implications. That said, it was a challenge and I had to re-read a lot of chapters to really feel comfortable with it.
I disagree with the assessment that it’s a poorly written book, but I can certainly understand why many would find it un-enjoyable. It’s not a science textbook, but it’s definitely not pop science either. Hawking pulls no punches when it comes to the concepts and doesn’t exclusively rely on analogies and metaphors. Reading the illustrated version probably helps a lot for some of the chapters.
IMO, anyone who’s interested should buy it and try reading it. Even if you don’t get it or don’t finish it, you’ll leave it impressed with the authors capabilities. Perhaps this is a bit tacky, but I feel like it’s one of those books that I like owning for the sake of it and having it on a shelf in my library. Right next to my Calvin and Hobbes anthology.
I also read it decades ago. I didn’t find it difficult at all but I have a graduate degree in engineering.
For anyone interested, here is a very entertaining alternative:
Bryson is an entertaining writer, but he has been widely criticized for the inaccuracies in his books. Here are some skeptics commenting on some of the issues in ASHoNE.