TITLE: How to use math textbooks
QUESTION [34 upvotes]: I'm a higher schooler who was recently gifted a book by my teacher (Schaum's outline of advanced calculus) which is really awesome and I've started working my way through it. 
I have run into a problem though. It is so incredibly different from high school textbooks! In high school, most textbooks (I've used) have like max an 80-20 exercise-theory ratio (with that I mean for every 4 pages full of exercises you have 1 page with theory. This book however (and I believe most university math textbooks have) has it extremely differently: first you get a couple of convoluted pages full with theorems/methods/rules (i.e. an information overload) and then you get dozens of exercises. So, I have a couple of questions:

Did anyone notice the difference too, or am I the only one?
What would you advise me to use as a supplement to this book?
Any general tips for a high schooler was has to go through this change alone? (p.s.- I'm extremely motivated to do this! Just skimming the book makes me so excited it's unbelievable. I just need some directions, and I hope I could get them here)

REPLY [2 votes]: I would look into courses on line like MIT's OCW or courseara. That was you can get a lecture to figure out what is important. I read lots of math textbooks too but it helps me to have a guide to sort out what in a textbook is worth your focus. I have the advanced calculus book you mentioned and I found it helpful through my graduate level courses, so it's not the friendliest book to start off your higher studies with. Good luck!