I almost never get headaches.
The last two days it's been humid, and I've had headaches. Related? Not enough data. Prior to the past two days, it was humid once 4 or 5 months ago, and that's the last time I remember. But I don't recall having a headache that day.
I was driving home from work tonight and realized at some point I'd forgotten most the drive. I started to wonder why the brain handles driving (which is pretty complicated) without even thinking.
So then I started thinking about driving off the road into people's yards and swerving at the last moment before hitting their houses/fences/etc. I realized I had absolutely no idea if I could and what it'd feel like to drive on grass. Would I slide? How well would I accelerate? The idea was really exciting. Driving fast is also exciting.
I generalized: what is exciting? What keeps the brain awake?
Events which the brain doesn't know how to handle (physics of driving on grass), where you have to both make a calculated decision (perhaps wet grass is equivalent to driving on ice, I'll use that as my model!) and observe the actual results (nope, grass is a little more sticky). Observations during/after actions... brain must be awake to coordinate/sync the processes?
Decision (to go fast) or situation (friend driving fast) causes lots of events (trees, kids, cars flying by) so there's a lot of input to process. No time to let brain idle. The penalty for ignoring an event (kid in the street) is more important, since the time between events and thus before the required action is so low. Must think quick. But driving slow, the brain can fall asleep and only check for kids in your path irreguarly, at a subconscious rate, since the time between the necessary required actions is so low.
Doing the same thing all the time, and doing it at a regular pace, lets the mind make its habitual decisions without having to observe the results at a rate that causes things to be interesting ("brain to be awake").
And it applies directly to life. Perhaps my boredom of late is due to doing the same thing over and over and not taking risks. I need to keep learning new things and be more daring.
I hate this humidity.