Fess: Well, you must admit there is something innately humorous about
a man chasing an invention of his own halfway across the galaxy.
Rod: Oh yeah, it’s a million yuks, sure. But after all, isn’t that the
basic difference between robots and humans?
Fess: What, the ability to form imaginary constructs?
Rod: No, the ability to get hung up on them.
— Christopher Stasheff, “The Warlock in Spite of Himself”