List of United States Presidents by military rank. The United States Constitution names the President of the United States the Commander-in-Chief of the U.S. armed forces. Many Presidents, however, also served in the military before taking office; all but 12 of 43 served. 1  1 Table of United States Presidents by military rank.  1.1 General of the Armies.
It is called circadian rhythms. Humans tend to sleep when it is dark out. I, on the other hand must work all night and sleep in the day. so my natural rhythms are screwed up. Being bored makes us sleepy, reading and watching TV makes me sleepy also physical tiredness.
Why You Need Sleep. The average kid has a busy day. There's school, taking care of your pets, running around with friends, going to sports practice or other activities, and doing your homework. By the end of the day, your body needs a break. Sleep allows your body to rest for the next day.