A joke that takes place before automobiles existed:
A rich man went on a trip with his own horse-drawn carriage and its driver. On the first night out, he stopped at an inn, took a room for himself but told the driver to spend the night sitting on the carriage, and insisted he stay awake to check thieves could not steal the two horses.
But the rich man's worries kept him from sleeping soundly. At 2am he wakes up, runs to the stable and calls the driver.
"Are you sleeping?"
"No, I'm awake"
"What are you doing?"
"I'm Thinking"
you could hear the capitalized verb
"What are you thinking about?"
"Every year, in the fall, the trees lose their leaves. All these leaves, year after year... Where have they disappeared?"
"Very well, keep thinking".
But the rich man still cannot sleep soundly. At 4am he wakes up again, runs to the stable and calls the driver.
"Are you sleeping?"
"No, I'm awake"
"What are you doing?"
"I'm Thinking"
"What are you thinking about?"
"Every year, in the winter, there are these big snowfalls. All this snow, year after year... Where has it all disappeared?"
"Very well, keep thinking".
Finally dawn arrives. Time to get ready. At 6am the inn is waking up and the rich man runs to the stable and calls the driver.
"Are you sleeping?"
"No, I'm awake"
"What are you doing?"
"I'm Thinking"
"What are you thinking about?"
"Throughout the night I've been awake, Thinking and Thinking.
And now, the horses... where have they disappeared?"