On average, infants sleep 20 hours a day, 1-year-olds sleep 13 hours a day, teenagers sleep 9 hours, 40-year-olds sleep 7 hours, 50 year-olds sleep 6 hours, and people 65 and older sleep 5 hours. As you get older, you spend more time lying awake at night and, once asleep, you’re much more easily aroused. The production of melatonin, which regulates the sleep cycle, reduces with age — one of the reasons why older people experience more insomnia. By age 65, an unbroken night of sleep is rare; 20 percent of the night consists of lying awake. As I constantly have to remind my now light-sleeping father, people ages 73 to 92 awake, on average, 21 times a night owing to disordered breathing.
– David Shields, The Thing About Life is that One Day You’ll Be Dead
Filed under: Big Picture, Quotable

Man … this is way depressing. All of a sudden I’m regretting every hour of sleep I forwent as a college student. *tear*