Stars:
Sherlock Holmes woke up in the middle of the night, as he sometimes would. Looking around the campsite, where they were staying, he had a sudden epiphany, which he had to share with John.
Several kicks on the doctor's sleeping bag later, and the man groggily managed to wake up.
"John." Said Sherlock. "If you look up there, what do you see?"
"Er... the moon? Stars. Millions of stars."
"And what do you suppose that tells us."
John sighed, clearly this was another one of his games. "Well, I suppose it tells us that the sun's not up yet..." He cast around for cleverer answers than that. "It tells certain people where they are. It tells astrologers whether tomorrow's going to be a good day... Oh, and it tells us that if there are millions of stars, there must be billions of planets and there's a high probability that at least some of them have alien life!"
"No John." Said Sherlock. "It tells us that someone's nicked our bloody tent!"
