As an example: anxiety about impending winter was a very desirable evolutionary trait for northern populations. Every year you realized that if you didn't have

As an example: anxiety about impending winter was a very desirable evolutionary trait for northern populations. Every year you realized that if you didn't have enough food for winter you and your family might starve. Obsessing over all the things that could go wrong helped you survive -- planning for things like failed crops, losing livestock, early or late freezes. The "chill" people without that intense pessimism about the future often did starve and we're not descended from them. But in modern life, the intensity of anxiety about an uncertain future is misplaced. It's a good trait to have still -- yes -- but it shouldn't be taking over your mind.