It's like trying to keep cattle in the pasture.
"I checked the north fence and it's secure."
What about the south fence?
I checked the north fence from one end to the other. I tightened the wire in a couple of places. It's good now."
What about the east fence?
"I sat there for a while and watched and nothing got out of the north fence."
Half the cows are out. A tree fell on the west fence.
"The north fence is strong. Why is that so hard to understand."