What does it mean, Watson?

In one of their adventures, Holmes and Watson needed to travel to a remote place. There was no house where they could stay, so they took a tent with them. As evening fell, they pitched the tent, and after they had eaten their supper they went to sleep in the tent for the night.
In the middle of the night, Holmes woke Watson and said, "Look up, Watson. What can you see?"
And Watson woke up, and looked. "I see the stars," he said. "There are thousands and thousands of them."
"And what does it all mean, Watson?" said Holmes. "What does it mean?"
And Watson replied, "Well, if there are millions of stars and even a few of those stars have planets, it is quite likely that there are other planets like earth in the universe. And if there are a few planets like earth in the universe, there might also be life – living things like us."
"You fool Watson," replied Holmes. "It means that someone has stolen our tent!"
Photo of Basil Rathbone as Sherlock Holmes in the 1939 film The Hound of the Baskervilles