Having "Blue Prints" of every system is key and I continue to draw them just to stay sharp. It doesn't distract you from more important items seeing systems knowledge is one of the most important. Have a great grasp of our a/c systems inside and out will save your ass someday. AND I don't mean during an emergency. Having a firm understanding can help assist maintenance control in fixing a minor glitch that's keeping you from getting home or maybe the FAA is jump seating you and some minor problem springs to life. Without a through understanding of systems knowledge (Ops Spec, Wx, Regs, etc) you might make a decision that causes the FAA JSer to question your expertise, not good. You don’t want to spend a few hours after a flight having to explain yourself to the FAA. All the material that they teach you in ground school and sim needs to be treated equally important.

I highly recommend creating a "Blue Print" of every system in a small note book that you can keep with you. Mine not only has systems inside but does and don'ts, Regs, Wx, Ops Specs and there’s even a section for things I've learned on line. It's amazing that these POS's can through at you!

Good luck, study hard and lesson to your instructors.