I was very much like a walled city. My thick, solid walls were essential with my old definitions because they made me feel safe and secure. Minor external threats were easily kept at bay, and it was only large threats that caused me any worry. I was safe.
But the problem I see now with my stone wall approach is that while my walls kept out threats they also hindered growth, just like with a city, because I had to make do with the area that the wall encompassed. There was some room to grow by adding on floors to pre-existing buildings, but any new, ground-breaking ideas were outside of the wall and automatically seen as threats. At best, I would have a scornful reaction to any concept too far outside of my comfort zone, if I didn’t reject it outright.
While I’m now busily dismantling my stone wall, I certainly don’t want to swing to the other extreme and have no boundaries. Letting everything in can’t be any healthier than keeping everything out.