"Do you know why fire engines are red?"
Uhhh...no. Why are fire engines always red?
"Two plus two is four. Four times three is twelve. There are twelve inches in a ruler.
A famous ruler was Queen Mary. The Queen Mary was a ship. Ships sail on the sea.
The sea is full of fish. Fish have fins. The Finns fought the Russians. The Russians are red.
Fire engines are always red because they're always RUSHIN!"
Just a little joke I've heard only about a hundred times this week.