I asked him why. He told me that there are billions of stars out there with life on them.
I'm not sure about stars--they're awfully hot--but there's almost certainly life on other planets. I've seen Carl Sagan do the math. But that doesn't answer the question of why aliens would WANT to come to Earth. The universe is so vast---what could an alien species want from Earth that they couldn't get closer and easier? There are moons with seas of methane gas, asteroids made entirely out of diamond, and ice balls in the Oort cloud with enough water to fill a hundred thousand oceans. Why come to Earth?
The patient said, "Maybe to make slaves of us."
I thought that was pretty anthropomorphic, since humans have kept slaves everywhere they've ever existed (one out of every three people in the Roman Empire was a slave). But any civilization advanced enough for space travel would find it easier and cheaper to make nano-robots than to come all the way here and make slaves out of us. How would they feed us? How would they "breathe" us?
He said, "Maybe to take our women."
Well, I guess that might be true. Maybe the aliens are after our women.
I guess we need to be careful.
Nurse's Note: There are millions of animal species on the planet. That's not including the plant, fungi, monera and protist kingdoms. It's pretty arrogant to assume that an alien visitor would come all the way here just to steal a human female.