It's good to know that it's not necessary to totally understand everything you read (or listen to) the first time through. I think that's one of the misconceptions people get from school's "read it and answer the questions" format. It's okay to skim through something the first time and just get a general idea, then, if you're still interested, go back and read for more detail later - maybe after reading or hearing something else, first, that clarifies those details.
But that's learning in the sense of "taking in information" - and learning is more than that. Learning also comes from doing things, exploring objects and processes, places and ideas. Much as I like storing up facts like a magpie, I do most of my learning by taking things apart and putting them back together. If I have a question, I'm as likely to look for person to show me what I need as I am to look for a book. I *can* figure things out from books, but often I can learn the same thing more effectively by watching someone else.
photo by Roya Dedeaux