Ask HN: How do you synthesize books that you read?

Generally agree.

There is a case for writing down the stuff you learned though (into your notebook, app, zettelkasten, whatever). When I try to note down a concept I learned, I feel like sort of explaining it to myself. And often, I will quickly discover holes in my understanding. A good note-taking software can also point out connections to other stuff (mostly in the form of other notes) I maybe wouldn't have made. Maybe others don't need that, but I am bad at making connections.

There are a few things you need to do:

- reread/rewatch/relisten (not necessarily the whole thing, just parts (and at varying intervals))

- talk about and/or explain it to and with others

- read negative takes on what you just read/saw/heard (not just positive ones)

- actually do whatever it is you think you've learned

I recently discovered I have aphantasia. I lack the ability to visualize anything with my mind's eye, it's just blank. As I've delved into what aphantasia is and how it affects my brain processes in general it became very apparent to me that what I learn, how I learn, and my ability to retain that learning are deeply tied to my inability to visualize and the coping mechanisms I've developed to compensate.

Visualization, just like every trait, is a spectrum. I would recommend anyone analyzing their learning methods to take the Vividness of Visual Imagery Questionnaire (available at https://aphantasia.com/vviq) and see where you fall on the spectrum. I am about as far on the aphantasia side as you can get but my wife is the opposite and is considered a hyper-visualizer. The condition was named from the visual aspects but it can effect all senses. I can't hear music or imagine what voices sound like. I can't do impressions of people, I can't draw, I can't play guitar, etc. Some people with aphantasia can though so it's not a hard and fast rule. But making those realizations about myself has lifted a burden I didn't know was there. I can sell my guitar and stop being frustrated about why lessons aren't working. I can stop trying to draw pictures that look nothing like my intentions. I can stop wondering why I have no memory of where my wife left her keys. Most importantly, I could identify my coping mechanisms and focus on improving them.

Exploring the differences between how we think and learn has been a huge help to me personally, professionally and with my relationships. Not many specifics for OP's question but I just want to share awareness of Aphantasia and help others start their own journey of self-reflection and improvement.

EDIT: I thought of one specific example of how I learn that may help. There is something about the physical aspect of doing that solidifies something into my memory. The cool part is the physical act of writing something down counts for me. I can write something down and then throw away the paper and I will usually remember it just fine. It's the physical motions that trigger my brain to form the memories.

This is me too. Learning by doing means making mistakes in real life rather than things remaining in the realm of intellectual exercise where everything is neat and tidy.

Some people have a linear happy path to learning — they seem to be able to acquire all the right knowledge and avoid mistakes.

But I learn from doing the wrong things — the resulting cognitive dissonance burns the lesson into my head. This is an expensive way to learn because you have to make a lot of mistakes and bear the resulting shame. But over time I learned to avoid fatal mistakes and make the merely stupid ones.

I’ve always been inspired by a quote by Goro Shimura about his colleague Yutaka Taniyama (both of the Taniyama Shimura Conjecture fame, which led to the proof of Fermat’s last theorem):

“He was not a very careful person as a mathematician. He made a lot of mistakes. But he made mistakes in a good direction. I tried to imitate him. But I've realized that it's very difficult to make good mistakes.”

Wow, I've always wondered if I was the only one or how to even describe it in one word. Thanks for this. I dont have much creativity because I can't imagine in my mind, I have to put it down on paper. I can't draw from my mind, can't put a tune together. But I can copy patterns well.