If you become a big reader in life (which I highly recommend), there’s no way to retain all of those details. But what happens is that themes emerge that are attractive to you. Certain books will introduce you to topics that are of interest.
That will cause you to read certain other books which expand on those themes. Soon you start getting an expertise in an area because you keep learning about something on a deeper and deeper level while testing those theories in real life to see if it works for your own personal situation.
I’ve read a lot of books that in hindsight didn’t really do much for me other than expose me to a different way of looking at things that didn’t seem attractive in my own life and viewpoint. That is still valuable.
The ultimate goal is to build mental models of how life works based on what we want to achieve and be able to implement those things to get what we want. If our life isn’t going as planned, usually something is wrong with our beliefs, assumptions, or models that we are using.
So we must change or adapt and do something different. Which is hard and that’s why people don’t do it. But the person who can adapt to get what they want eventually has a good chance of achieving some success.