I didn't sleep much last night and generally that's no way to begin the week. Today it proved a particular challenge while I was teaching ancient Chinese history to my freshman in the morning. I was explaining that peasants built earthen dikes around the Huang He River to protect their crops from periodic floods.
And I write dike on the board.
And (you can see this coming, can't you?) yes, I spell it dyke.
I quickly fix the spelling error and make my standard joke: I need spellcheck for the chalkboard. The class doesn't seem to notice, though I fear they were just being kind.
Several hours later, I'm still embarrassed.