Many a battle is fought and won at the weakest point in your fortress. When enemy forces attack a fortress, they usually aim at its weakest point. Sometimes they launch a surprise attack hoping to break in through what their spies have found out to be the weakest point. But if, in the meanwhile, those within the fortress have already taken precautions to fortify that vulnerable spot, the enemies will themselves be taken by surprise when they attack. Then they will not only be repelled but fully conquered and subjugated.
So one's weakest point could well be the starting point on the road to perfection, failures are the pillars of success.
Even as a frontier fort Guarded within and without So should one keep guard on oneself Not to let the moment to slip by For they that let the moment slip by Slip down into hell-only to cry.
- Dhp.v.315
source: www.lanka.com/dhamma/ttw/ttw_main.htm