Reading can help, but reading without note taking and summarizing is much less effective. You need to actually force the brain to incorporate the essential points of what you read. You need active learning, not just reading, which is, in itself, passive.
And marking up a text with a highlighter isn't much better.
What you really should do is take notes on what you read. For each chapter of a book, for example, immediately summarize what you see as key points by writing them (preferably by hand) in a note book.
Then, summarize your notes by reflecting on them and, again, extracting the most important ideas. If you do the last part on note cards then you can build yourself a deck of "ideas", one per card. These cards can be referred to later. But several of them can also be carried around with you for reference and reinforcement. You will have moments during the day when you are idle. Pull out your few cards and a pen and review what you have.
Number the cards as you create them (so you can reconstruct the deck). Say which book/chapter/article they came from. Don't try to fill up the card. In fact, initially leave the back of the card blank so that you have a place for annotations later.
But the real key to all of this isn't the cards themselves, though they help. It is the mental effort you go through to create them, which is a reinforcement mechanism that reading alone doesn't provide.
The real goal is insight into a topic.
I read a lot of unimportant stuff. But most of it disappears as soon as I start the next thing. This is fine, since I have no need to remember. On the other hand, in professional work, once I'd achieved insight into a topic, I could listen to a conference speaker and mostly not take notes. The speaker would either reinforce insights I already had, so there was no need to capture the ideas, or they would challenge those insights. In the latter case I had work to do, notes to take, further explorations, summaries, revisions, new insights (hopefully).
A note on highlighters.
I've seen student texts in which nearly every sentence is marked. This is worthless. The marking was almost certainly done while the student was reading.
However, if you make highlighting a part of a secondary (or tertiary) process, after you've reviewed the entire, say, chapter, then it can have some value, especially if you limit the number of sentences that you allow yourself to mark. Now, the work has an outline if big ideas that you created after thinking about it. The printed and marked page can now be used for review. However, you can't carry a bunch of books around everywhere like you can a bunch of note cards.
