why we sleep

You know what happens when you clock less than 7 to 8 hours one night (good morning, grumpy!), but when sleep loss goes on longer than that, the effects get much worse.
With so much to do each day, so many notes to study, so many hours of work and chores, sleep can, quite honestly, get in the way. If only I had all that time back!
Sleep and attention regulate each other "like yin and yang."
When your body is at rest, your brain is hard at work.
A number of proposals and perspectives have emerged that, taken together, paint a compelling and converging picture of why sleep evolved and why it is now needed.