I’ve long had the same concern, and developed a solution recently. I wrote a book.

What I’m doing is when I’m reading a book, I taking notes and underline all the sections that Interest me, then I compile them into a book, I’m using Vellum, which is a print layout tool.

Then, every month or two, I go to Lulu.and I print it out. I try and read half an hour or so every night before bed, and I keep editing. Move things around. For instance I read and took notes on three management books, and now I’m slowly and iteratively combining the notes. Adding my own color, keeping direct quotes I may hear from friends or colleagues, movies and tv, or famous historical figures.

It’s fun because I think one of my core values / goals in life is around creating things, and working on this as an actual artifact I can hold in my hands fills that desire.

I have the same exact problem! I'm super impressed by people who can read books and memorize the details. And I tried really hard to do the same.

So here's a different perspective on solving this problem: don't bother!

I'm sure you have other strengths. Lean into those and don't worry about trying to be the guy/girl that can recall details from books. Life gets much easier when you don't try to fight things that don't come natural to you.

So what do you do about your non-fiction reading? Keep reading! You may enjoy it more when you're not trying to read with an agenda and you're relieved of the burden of trying to memorize. Even if you can't recall the details, your brain will be folding ideas from what you're reading into the things you're working on and you'll have breakthroughs.

What happens for me is that I read some books that resonate so much for me that they become my "bibles." I can't remember all the details, but they're helpful to me in certain periods of my life. I come back to them every few years or when I think they'll be particularly helpful for something going on in my life and I get to read them with fresh eyes and new perspective.

You don’t need to retain it. It’s an artificial problem.

What is important will retain automatically by your subconscious.

And there is not much unique net new information in nonfiction books to begin with.

90% of it is a garbage made up with sole goal of getting into your pocket.

9% is rephrasing and redigesting same thousand year old ideas.

And 1% is small and memorable enough by itself.

You'll remember some parts, you won't remember other parts. That's just the way it is.

I split nonfiction in two categories:

- Technical which teaches skills,

- And knowledge, which only updates my understanding.

There's no point in memorizing for the first one. What's needed is pure practice. So after the first read (which can be chaotic and not a linear process), I only place landmarks there to refer too when I need to practice or needs a solution or some information when facing a problem. Retaining will happens naturally as I interact more and more with it.

For the second one, I also don't need to memorize. All that is needed is thinking. By explaining the concept to others (mostly my SO) or using it as a lens for some situation I encountered (or possible ones), I make the idea my own. Anything else is not worth remembering.

I seldom take note. When I do is because the quote is nice. Or I summarize a page (or a chapter) of content down to some actionable ideas.

Either you remember or you dont. My gut feeling is that careing about remebering is not good. Reading out of pure interest is good. Technical/text book's are generaly layed out in an arbitrary fashion, so I read them randomly, skimming, skimming, looking for the gems, these books are in fact poor representations of what is in the minds of the people who were "professing" there knowledge, and often there are books written outside of the curicula that are musings and collected essays, shorter books with much more in them, on the same subjects. or single subject encyclopedias that function as handy reference books, just so that you dont have to remember everything

I take hand written notes. I can usually remember where something was written if I forget the core details, so I can look it up quickly referring to my notes.

For me I can’t do typed or device drawn notes. Idk why but I just don’t remember as well if I type out notes instead of write.

I reread them multiple times

You don’t need to remember everything, that’s exactly why the information is in a book in the first place. Just keep a physical or digital library and you’ll have everything you need.

I crave that thing what am I reading. For example, I have a political/philosophical point of view and the more books I read the more broad my PoV becomes.

And man, psychology and business are not a nonfiction. If you are reading some fiction don't complain you don't remember anything - this forgetting is called a decent brainwork.