This story was brought to mind this morning because when I stopped for gas Mom read a sign that said "No Smoking Propane". When I got back in the car Mom asked what propane was and I said it was a gas. She said "That's what I thought. How would you smoke it?" I started cracking up and explained that the sign meant No Smoking because there was propane in the area. Mom began laughing and for a moment we were having fun. Then, as we were pulling out of the gas station, Mom looked at the sign and again asked "What is propane?"
Oh well, it was good for a momentary laugh with Mom and it brought back a happy memory.