Honoring the hardened heart

The image that came to my mind as I read this section isn't the greatest, but I thought I would share it, since it's what popped into my head right away. Sarah talks about the "armor" we put around the heart to protect it.
I was thinking in terms of a cast. Like when you break a leg, they put this thick, heavy cast on it to help it heal and protect it from further damage. The cast serves its purpose to a point. But then it needs to come off. If you just kept the cast on, it would eventually cause more harm than good, as your leg muscles atrophy. So for ultimately healing of a leg break, the cast is cut off, and the strength of the leg is gradually built back up. The process makes sense.
But when it comes to the breaking of the heart, I think we sometimes put the cast on to protect it and heal it, but then grow accustomed to living with the cast, even though it is heavy and weighs us down. We skip that last step of breaking open the cast and taking it off.
So if we give thanks for the cast and its protection, we can also recognize that a cast that's been on for a long time starts looking pretty gross and grungy.
How do you visualize the hardened heart? How has armor gotten you through difficult times? What limitations has it caused for you?

- Melanie