I had my neighbor's five-year-old grandson in the car and, for reasons that only a five-year-old would understand, he chanted "Bananas!" about five hundred times during a fifteen-minute car ride. I thought it was funny. My son morphed from a grumpy teenager to a grumpier old man and started threatening suicide. I tried to teach the Little a "Knock Knock" joke but couldn't get him to say "Who's there?" After five minutes or so, my son was threatening to jump out of the car. I tried to convince my son that he had been WAAAAYYYY more annoying, but couldn't convince him, even when I reminded him that I once literally thumped him on the head with a Bible in church.
I cannot wait for grandchildren. Now I see they are the ultimate revenge on your children.