How do you find a balance between too much concern and not enough?

I come across people who basically refuse to take seriously any suggestion that there’s anything to worry about. They live their lives with a cocky insouciance, shrugging off warnings and alarms, poking fun at hand-wringers.

And I come across the opposite: people who are so hyper-vigilant about possible dangers and negative impacts, etc. that they live as if they’re tiptoeing through a minefield. I was talking to a guy a couple of days ago who refuses to use a cell phone, won’t drive a car, buys only hemp garments, and eats only organic local foods (I could go on and on). He struck me as a neurotic mess whose every little choice in life was a high-stakes game.

The first kind of person, “Mr. Blithe”, arguably enjoys a more stress-free life, and isn’t inconvenienced by any compunctions as he goes about his business. But I shudder to think about a world where everyone was like that.

The second kind of person, “Ms. Cassandra”, seems unlikely to be enjoying life much. There’s a constant fear there (and often anger to go with that). This is a very difficult and inconvenient life. But then, a world full of people like this might be better off in the long run.

I’ve just described the extremes of the spectrum, but there’s lots of middle ground. How do you steer your course?