" An ant has an easy mind to read. There’s just one stream of big simple thoughts: Carry, Carry, Bite, Get Into The Sandwiches, Carry, Eat. Something like a dog is more complicated—a dog can be thinking several thoughts at the same time. But a human mind is a great sullen lightning-filled cloud of thoughts, all of them occupying a finite amount of brain processing time. Finding whatever the owner thinks they’re thinking in the middle of the smog of prejudices, memories, worries, hopes and fears is almost impossible. "
― Terry Pratchett , Witches Abroad (Discworld, #12; Witches #3)