I struggled with fatigue for most of my sophomore year of high school. I started falling asleep in class out of nowhere. Then, as suddenly as I started falling asleep in class, I stopped.Looking back, I realized that I had been going days and weeks without seeing the sun. None of my classes had windows, nor did the lunchroom or the gyms. I had been getting to school early for clubs and leaving late because of sports. I was arriving at school before sunrise and leaving after sunset once the days got short enough.

Speaking of forests -- I think schools are overly concerned with controlling the environment kids learn in. I personally think that letting the mind wander for short periods helps your mental stamina recover.