LOL I know what you mean. You have to tend to one complex thing at a time, fully grasp it, then move to the next big thing. Overtime you try to interconnect the pieces, trying them together into a coherent whole. 
Good saying dear friend. Complexity = the result of many other interconnected concepts. The best path is to truly "overlearn" each "building block" of the complexity before trying to tackling the complexity itself. (like driving a car, which is a complex operation, composed of many simpler concepts, like using a gear stick (non automatic cars), following traffic rules ++). But before each "fundamental" = firmly integrated as an unconscious process, the brain has to compute stuff for each fundamental consciously, WHILE doing the complexity as well. That = highway to hell. Ever had a "brain overload" while learing how to drive?

This = the primary reason for why many people struggle with mathematics. Math = cumulative. If you fuck up with one fundamental (not integrating it properly in your mind with proper memorization and repetition of exercises for skill integration), you will eventually struggle.
Debussey feels that Johnny Falcon has what it takes to master physics.