I had marked the company night locations on my map with my grease pencil. I had a black, and and red and a green in my pocket. Later when it got dark I had to consult my map for some defensive targets. When I looked at it under a poncho with my flashlight... all of the locations had vanished. What happened?
The answer was that he had marked the locations with the red grease pencil and had a red filter on the flashlight which made them seem to disappear. It was easy for me... I think I remembered the occasion.
I was sitting in the back yard swing tonight as the BBQ was doing the cooking and I was sucking on a beer and smoking a cigar and remembered a like quiz I could have told him about ...but didn't because I wasn't thinking of it at the time.
Once, when I was the acting FO the CO came into the company TOC at Ben luc. He said to me.. I've got to insert a platoon by air this afternoon for a night ambush and I don't know if the arty here can support them. I asked him where. He gave me a grid and I went to the map on the wall and made a grease pencil mark. Then I went to the table and tore off a sheet of legal pad and went over to the map and made a few notations on the paper and told him... that's exactly 7200 meters from the battery here so no problem. The CO..being infantry thought I was pretty smart. It was pretty simple for an arty 13E20 to do. So how did I figure it out that quickly?