Supposing a pair of extraterrestrials from the vicinity of Deneb are orbiting Earth, preparing the attack.

“All right, Zarquod, I haven’t got all day.  Sum this planet up in a few words.”

“Yes, sir.  The Earthlings are creative, stubborn, selfish, and altruistic.”

“Well, which is it?  Selfish or altruistic?”

“No, both, sir.”

“You can’t be selfish AND altruistic!”

“They really are that screwed up, sir.”

“… You know what?  Never mind.  This planet is giving me a headache.”