Don't read to remember everything (that's virtually impossible for most people), mostly skim to build an index of concepts and possibilities in your mind – and

Don't read to remember everything (that's virtually impossible for most people), mostly skim to build an index of concepts and possibilities in your mind – and leave the details to the reference materials. Don't even bother to try and remember details for something you don't immediately need. Computers are good at details, humans are good at high-level webs of concepts. You also need to be comfortable with stopping at a certain layer of abstraction and mostly trusting that abstraction holds. For many programmers (including me) I suspect that's the model of a computer presented by C. I don't really bother to try to understand much of what's underneath this model because time and my brain is regrettably finite. I just know more or less what it's meant to do and trust it works. (Trust that, as evidenced by Spectre/Meltdown, is unfortunately misplaced, but still – I'm only one person.) If I had to attack trying to understand, say, PostgreSQL, I would find out what sort of thing it is (an RDMBS), what sort of ingredients that has (a network protocol, a query parser, fundamental data storage structures, etc) and fill in detail as my interest takes me. There's always going to be more to learn about – these are massive subjects – so it's always going to be piecemeal.