The Earthlings behaved at all times as though there were a big eye in the sky—as though that big eye were ravenous for entertainment. The big eye was a glutton for great theater. The big eye was indifferent as to whether the Earthling shows were comedy, tragedy, farce, satire, athletics, or vaudeville. Its demand, which Earthings apparently found as irresistible as gravity, was that the shows be great. The demand was so powerful that Earthlings did almost nothing but perform for it, night and day—and even in their dreams. The big eye was the only audience that Earthlings really cared about.
Source:Chapter 12: The Gentleman from Tralfamadore