Understand the single idea the whole course is built on: your brain can only hold a handful of things in mind at once, so you learn to improvise by "chunking" knowledge into long-term memory and using slow, deliberate practice (System 2) to train fast, intuitive playing (System 1). You'll see why limitation exercises — drastically restricting your options — let you absorb more about each new skill while still leaving room to play musically.