Golf tips are like aspirin. Take just one, and it will probably do you good. But if you swallow the whole bottle, you'll be lucky to survive.
I really like this quote. In fact, I wish I had read it 2 years ago. It would have saved me so much hassle - trying to robotically memorise every last detail of every class, and then never being able to pull off any of those cool escapes and submissions because I was thinking too much.
I find it much easier to just focus my attention on one or two things per class. This way I can slowly but more reliably (I don't like the use of the word "surely" in this context) grow my game, instead of trying to cram for exams before every class and praying that I can remember enough to survive.