It is actually extremely abnormal to remember everything you've read.

Yes the limitations of memory are normal. There is variability depending on the person and how interested you were in the book.

no you should be able to recall every single word you've ever read for your entire life

Normal. When reading it goes to short term memory. If you're not using or reviewing it, it's not going to go to long term memory.

It's fine. There were times when I reread a book, and I can't remember any of the things in it. Other times just after finishing a book I can really not remember any details except give you a very vague description of the book. It's like I read the book but didn't really read it.

At 66 I can't even remember the titles of the books I have read in my lifetime.

Sometimes I’m describing one book when talking about another and get so confused when I’m corrected 🧍🏽‍♀️

Most people forget things they're not using. Since you couldn't come up with anything at all and it's just this one book, and not up to date psychology, it sounds like you're not that interested and maybe were expecting something different, though.

I would have no problem recalling many of the main details from having studied psychology, but then it was more concrete, studies, diagnostic criteria applicable to real people. You may not be able to remember because it was a psychotherapy book and wasn't really saying anything, just waffle trying to sound meaningful, that stuff is bunk, so it's not surprising if there was nothing for your memory to keep hold of.

Absolutely, some more than others. I find that I tend to remember details more when something important in my life is happening at the time of reading, or bits that really left an impression on myself.

Guards! Guards! Will forever be ingrained into my memory for I read it while traveling through Europe for a month, or Dark Matter because I read it in the hospital waiting for my son to be born. Yet I barely remember a thing from American Gods and I couldn’t even tell you the year I read it.

Use it or lose it. When most people 'read', they merely run their eyes over pages, getting little more than fleeting feelings of happiness when they find ideas that they agree with. Even those few people who try to digest every tidbit of information in a book seldom apply what they learn on a daily basis. So they quickly forget much of the information. For most people, including you it seems, reading is a diversion - nothing more.