First there is the Comfort Zone, then there is the Stretch Zone, and finally the Panic Zone.
To enter the Stretch Zone is to give up your comforts, securities, and to trust that everything will be okay.
To enter the Panic Zone means you have been pushed too far and usually means you just give up.
To watch someone walk along a pole five metres in the air is comfortable for most people, to do it themselves is either a stretch or a reason to panic. But of course having done it and found themselves back on the ground and still alive, they want to do it again (mostly). It's the way it goes with most things. Until you trust you won't leave your comfort zone.
Still working on that.