You won’t remember everything you see, read, or hear. There are plenty of studies for you to consult on whether you should be reading, watching, or listening to your educational material. You could become paranoid and try to figure out which is the absolute best before you decide on one way to learn, but that would be counterproductive. The best book is the one you are reading. If you’re reading a book on audiobook, then that is the way you’ll best learn. If that makes you more likely to receive the information, then what does it matter that you’ll retain more of what you learn in printed books? You’re not reading the physical copies anyway! It’s also a game of numbers: If you can process 40 pages of a book in a day via audiobook versus 10–15 on a paper copy, then you can get through the content quicker and look for the real gems.*
My number one piece of advice to you here is that whenever you are reading, you must focus. You can’t afford to doze off. That is for later when you intend to let your mind to wander rather than to study.
*A few months after writing this, I moved away from audiobooks because I found it was too easy to get distracted and miss two to three minutes at a time.