Is full-time work bad for our brains?

Mind you, all of this is technically optional. I went to a well-funded high school in an affluent suburb, and there were certainly students who had schedules like yours -- I personally knew quite a lot of people whose high-school lives resembled yours -- but there were also a bunch of slackers who just didn't do anything. For as many people like you I knew, I knew just as many stoners (including two guys who were sent to the alternative school multiple times a year because they were too stupid to not get caught with weed on campus). I even knew a few people who dropped out.

I followed the middle path, taking advantage of a quirk of Texas law. You see, I have less than zero interest in athletics and little to no interest in other after-school activities. I wanted to go to college, and my dream involved getting a CS degree, but I couldn't care less about getting into some prestigious private and/or out-of-state school or what have you.

This was good because I live in Texas, and Texas law requires all state universities to accept any in-state student who graduates in the top 10% of their class. So I just made sure to do well in my classes. I participated in virtually no extracurriculars (except one club that only met sporadically because I had a personal interest in it), I took exactly one AP class because I knew I'd breeze through the material (AP CS 1; I would've taken AP CS 2, but it was cancelled my senior year due to lack of enrollment), and I only took a small handful of PreAP/Honors classes because they were in subjects I knew I was good at. My lack of extracurriculars helped me to have the energy to pay attention in class, and I took easy classes (well, easy for me). Hell, I was so good at paying attention in class that I could do virtually no studying outside of class and still ace almost all of my tests. My evenings were free as a bird. As such, I made straight As (and often A+es, which counted for GPA in my high school) in almost everything with little effort. I made the top 10% with about a dozen students between me and the cutoff, and I went to a very nice state university that's known for its CS program.

I made some incredible friends in college, who I'm close to to this day, learned a lot of things that I still use in my thirties, and those four years at a state school were the best years of my life. Whatever else I regret in my life, how I went about my schooling wasn't one of them.

If you're obsessive about sleep, I think you'll be fine :) My mistake was doing 3 20 min sessions of pretty intense HIIT a week and then not getting nearly enough sleep (averaged maybe 6 hrs). I felt chronic fatigue at work - it feels like a heavy wave of exhaustion very different from typical feelings of tiredness. You'll notice your work performance degrade correspondingly. Under normal circumstances you might be able to get away with bad sleep for a handful of days or even a few weeks. Not so with HIIT. You have to have an athlete's level of attention to your recovery.

All that said, HIIT is the most effective kind of exercise I've encountered and I recommend it wholeheartedly!

Yes, I should have mentioned that I went to a modestly-funded public high school in a small dying steel town outside of Pittsburgh, Pennsylvania -- most of my classmates were the aforementioned stoners as well (they graduated to heroin -- indeed, my county has one of the highest rates for heroin abuse in the country).

For some reason, I believed that I was destined for a better life, I really loved computer programming and I wanted to live in Silicon Valley, and I worked my ass off for it. There were no handouts, and I knew I would be judged with the same yardstick as the kids from the likes of Phillips Exeter with their near-perfect SAT scores, the byproduct of personalized tutoring. The web site College Confidential was my bible. I'm one of the few that left the town, and now I live in Silicon Valley.

Still, I got thin envelopes in the mail from all but one of my reach schools. I took the opportunity I had and ran with it.

I have zero regrets as well. Turned out that playing one hour of Counter-Strike a day instead of five had a much bigger payout.

I didn't mean "slack" as in "free time because there isn't anything to do"; I meant "slack" as in "extra tolerance because—at a given wage—an average employee will predictably goof off X% of the time."

This is how all large chains (McDonalds, WalMart, etc.) are managed from a corporate perspective. Instead of paying X salary to ensure enough "morale" for optimal worker productivity, it is actually more cost-effective to pay workers a lower wage such that they're sub-optimally productive—but still productive—and then put systems in place to both idiot-proof and peer-quality-check each employee's output, such that the output is still guaranteed even with multiple "malfunctioning" process-nodes potentially touching it.

The epitome of this approach is seen in how an "automatic" Amazon Mechanical Turk work pipeline operates at scale: a program hands off work-items to workers, and then treats each individual work-product as being of unknown quality, handing it off to further workers to give a quality-judgement to it, cross-checking those workers' opinions in case some of them are just mashing "good", etc. None of this would be necessary if the work paid well-enough for market-forces to apply (i.e. if people would want to compete for the work.) But since it doesn't pay, people aren't interested in one-upping one-another's quality to steal the job, so you just end up with whoever decided to wander in.

See also: the economic "Losers" in the MacLeod Hierarchy.

Why not include insignificant terms in the regression? Maybe because they're insignificant?

I understand what the regression is doing. The authors understand. You do not, though.

You've already admitting not to having a background in stats, yet you keep throwing around words like "significance" and "model fitting" without having the faintest clue what they mean mathematically. I'm sorry, but I can't fit several semesters of undergrad-level stats in these comment boxes.