I heard an interview with comedian Jeff Foxworthy in which he said (and I am paraphrasing here), “I wish I had been a singer. My singer friends can write three good songs and then get paid to sing them for the next 40 years. People love hearing their old songs. That is not true with comedians. I can write the best joke ever and it has a lifespan of three months. After that, no one laughs, and they never want to hear that joke again”. Why is that true? In part, it has to do with the fact that comedy relies on surprise. We laugh because ...