Occupation That Has Remained True Over Time: Sleep

There is one occupation that has stayed true over time, and is essential to our life: sleeping. No matter what century, decade, or millenium, sleep has been a part of it. Without sleep we would not be able to function as members of society and we would slowly breakdown. We  have found a way to get more comfortable as a society when going to sleep. I, personally have a strong attachment to my orthopedic pillow and heated blankets, but the fundamental process of sleep is the same today as it was 1,000 years ago.