Mulla was relieving himself in an alley next to a leaky water pipe. Hearing the continuous trickle of the pipe, Mulla thought it was the sound of his own stream. He just stayed squatted there, waiting to finish. Two hours later, a friend walked by and asked, "Mulla, what on earth have you been doing in this alley for two hours?" Mulla groaned, "I don't know, I must have caught a terrible disease because I just can't stop peeing!"