Today was my last day of work until January 12th, which is 23 days from now. I'm trying to finish a particularly difficult book in the next couple of days so that I can officially start the first course, Macroeconomic Theory, of my A.E. Project.
The book is Development as Freedom by Amartya Sen. I find myself dozing off or zoning out through relatively long stretches of the book, which is uncommon for me and usually the result of difficulty, not boredom - honest, the ideas are really interesting, I promise! Even though it is a pretty big act of volition on my part to keep going, there is one simple reason.
This is a concept from strength training and is illustrated in the picture above. Progressive overload is the gradual increase of stress to the body over time. You can see in the picture that as performance comes to a new peak, a training session happens. This training session should result in a larger stress than previously encountered by the body causing a momentary dip in performance. After proper rest and recovery, your body adapts to the stress by supercompensating to a new local maximum so that future stressors of the size just encountered aren't seen as a shock to your body's equilibrium.
By gradually increasing the stress endured in a training session over time, with the proper rest and recovery between sessions, the body continually gets stronger (or faster, or "insert goal here").
If you do not expose the body to a larger stress, there will be no momentary dip, since the body is already adapted to all stressors smaller than the previous training session. The stressor must be large enough to elicit the dip or there will be no reason for it to supercompensate to a higher performance level.
This is why people that lift the same weight for the same number of reps for the same number of sets each time they go to the gym don't get stronger. The same applies to running the same distance in the same time frame and every other physical aspect you can think of.
It also applies to learning.
This is why I continue to read books that are just beyond my ability and cause me to strain and be uncomfortable. Even though Development as Freedom is quite difficult for me to get through, I know it is causing that momentary dip (recognizable as mental fatigue, zoning out, or other attention issues).
As long as I keep pushing, I will come out the other side. Perhaps not right away, but eventually.
This same idea is one of the largest reasons for me wanting to undertake the A.E. Project as well. I'm sure that there will be lots of strain and stress (the good kind), but eventually that will translate into a higher performance maximum, just like with the diagram above. Each course will act as a "training session" that my mind will be forced to adapt to.
Lift heavy shit. Read hard shit. Dip. Adapt.