The violinist Fritz Kreisler was out strolling with a friend when they came upon a fish market. Kreisler looked down at the fish, seeing row upon row of staring eyes and gaping mouths. Suddenly, he smacked his hand to his forehead. "I'm late for a concert!" [I read this years ago (source forgotten). It was claimed to be a true story.]
(From the "Rest" of RHF)