Just got one–a good, wide-brim, adjustable bucket hat. Shade during the sun, solid protection from the rain, comfortable, and not too difficult to make look decent, if not stylish.
Don’t get me wrong, education, housing, health care etc have all been pretty important too, but hat wins.
You can’t escape the inter-connectedness of human body systems. Improve something somewhere, something else gets changed too. This is why being a doctor is so hard.
So, it’s only true from a 19th century understanding of science. Which a lot of people admittedly prefer, because of how simplistic it was. It’s a lot easier to feel like you understand things if you just ignore all the complex and hard parts.