When our middle son was a young teenager, one of his chores was to mow the lawns. One day as I walked into the house after work I noticed that the front yard had dandelion stems in it that were at least 6 inches tall. On top of them were the round puff-balls that blew apart on windy days. My son had promised to mow the yard the day before, but looking at those tall dandelions it was clear to me that he hadn’t done so.

I asked him if he had mowed the lawn the day before, and if he had, whether he did a good job. He answered yes to both questions. By now, I was getting angry.

I asked him how he could possibly have mowed the yard the day before when the dandelions were so tall today? He swore to me that he had indeed mowed…