The sheer irrational nature of a dream boggles my mind. Many a curious phenomena make an appearance in a single dream, weather simple or complex. Odd behaviors such as mass hyperbole and outrageous gesticulatory conversation amass themselves in the dream so well, that to our own person, it feels as if it was the most natural thing in the world. Only when we wake up and verbalize our dreams do we realize how plainly silly they really were.
Another exquisitely complex behavior is the act of 'sleeptalking'. Personally, sleeptalking perturbs me. It is disturbing to know that people may listen to what one is dreaming.