This is the most well-known method to make a person to go to sleep, being treated as "Father of Hypnotism". By doing some repetitive and boring things, our brain feel sleepy, and we will fall asleep eventually. The main point of this method is to think of many little sheep flying across the fence, and counting them one by one. As we heard from others, this method is so called because the word "Sheep" sounds like the word "Sleep". This may be the reason why some people still awake while counting hundreds or thousands of sheep. Maybe we should use English to count!!!