Read more papers. That's my biggest lesson from college and it took a few decades to sink in: Papers are your best source of distilled knowledge.
Back in college we had this gnarly information and queuing theory class. I kept banging my head against that exam for 2 years and couldn't pass.
Then I said fuck it, ignored all the textbooks and the lesson notes and the professor, and read Claude Shannon's original paper. My friend, A Mathematical Theory of Communication is one of the best papers I have ever read.