Some people put up brick walls to keep others out. Others put them up, just to see who cares enough to knock them down. Sometimes, I'm afraid of what will be on the other side of these walls as I take them apart.
I have a picket fence and a gate with a lock on it. You can see over it, but must have a key to get inside, which most do. But what lies beyond that are various doors, some open, but most closed. Sometimes I accidently leave a door open and people go through and that scares me.
There is one door that remains locked at all times. Some have found the key, but only a few have been allowed to stay and will remain there forever. Others have caused pain or hurt, so the locks have been changed and now they must find a new key, and a new way to get in.
