Common Sense :)

An illiterate father with his educated son went on a camping trip, they set up their tent and feel asleep.

Some hour later, father wakes his son and asks: "Look up to the sky and tell me what do you see?

Son: I see Millions of stars...

Father: What does that tell you?

Son: Astronomically it tells there are millions of galaxies and planets up there...

Father: Slaps the son hard and says, "Idiot, someone has stolen our tent!"