There's stepping out of your comfort zone and then there's firing yourself like a human cannonball into the flames of high anxiety. Before my layoff, I was doing the latter on a daily basis. And I think many of us can’t see the difference between the two.
When we step out of our comfort zone, just like animals in nature, we're surviving a perceived threat. This stress response is designed to be fleeting, to help us when we're under pressure, not to be a default way of living — or working.