Remember that fog we had last November? I had to venture into it early that Sunday morning. I left home about 6:00 a.m., long before most people even thought about getting up. The fog was dense. My automobile headlights would not cut it. Visibility was reduced to about ten feet. I turned on my dimmer lights and hoped that on-coming traffic would do the same. As I drove, I felt like my car was pushing through a tunnel of smoke.

I was able to drive from my house to the church because I had driven along that route so many times. I knew the hills, curves, landmarks, and the names of intersecting streets. I knew when I was passing the college, the elementary school, the international restaurant, and the grocery store. I knew when I was passing those places, not because I could see them, but be…