

In my mind it’s because starting training to take care of your physical health is one of the first steps toward training your brain to take care of yourself as a whole.
It’s also a lot easier to feel better about your existence if you have the physical ability to do get up and spend it doing something that gives you joy, like going for a longer walk than usual because the weather hits right
There’s also potential link to how we as a species have survived- we had to keep moving to stay alive, so our brains throw a wobbly if we don’t.
Had a pair of red lens aviators back in the day and my god did they make my brain happy, 0% blue light, everyone looks at you like you’re some kinda weirdo (and the weirdos know you’re one of them). Only downside is everything goes green when you take them off.