A consistent lack of sleep wreaks havoc on your body and brain. Want to quickly test if you're not getting enough sleep? Hit play on this video.
Besides the test in the first part of the video, In 59 Seconds' Richard Wiseman points out three clues you might be sleep deprived: needing to wake up with an alarm, falling asleep within five minutes of lying down, and relying on caffeine to get through your day. Falling asleep quickly is the most surprising one (since many of us would love to fall asleep faster), but the point is probably that if you're always asleep as soon as your head hits the pillow, you're probably dead tired all the time and should get more rest.