Guarding your heart is something you do when the possible pain is too overwhelming to imagine. You cannot gaurd your heart when you parent a child.
I repeat this about a hundred times a day :). Grant me the serenity to accept the things I cannot change;
Courage to change the things I can;
And wisdom to know the difference.
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace.