That’s biomechanics and the main thing you learn in it aside from statics and dynamics is that living osseous tissue is a strange material and it bends so much more than you think it should
I work at an understaffed convenience store/fast food fusion. The amount of people who make their dogshit life choices my problem makes me look longingly at tall bridges.
Also, humans are not machines, we need rest and relaxation. It's debatable for why, but life would be a lot more boring if we didn't have a need for relaxation, art, recreation, etc. Just pure work for survival.
Cortisol is actually a really important hormone and it can even make you feel good. The problem is when you have too much too often. It’s like putting your body and mind into sport mode. Very useful in the short term but unsustainable in the long term.
A successful organism would not have evolved to highly express cortisol to weed itself out in the case that it has a stressful life. It makes no sense for an organism to evolve a trait that makes it at best equally likely and at worst less likely to reproduce.
The reason we release excess cortisol in modern life is because our bodies did not evolve for constantly present stressors, they evolved to be stressed in a situation, run away from the tiger, and then you're good.